I don’t remember when my sister and I began baking cookies together, but soon it was a permanent fixture, the ritual of our childhood. Every Monday at seven o’clock, our mother would drop me and Cecily off at our father’s house. Ingredients were waiting for us when we arrived, arranged on the counter in neat rows by our hyper-organized, sweet-toothed father. The oven was already preheating, and two sticks of butter, swaddled in wax paper blankets, warmed slowly on the stovetop.

As soon as we stepped into the kitchen, my sister would begin to give orders, her thick brown hair pulled into a severe bun, and I, her dedicated sous-chef, would obey her every command. The recipe was always the same; our muscle memory guided us through each measurement like a well-rehearsed dance.

“Small bowl. Dry ingredients,” my sister would bark.

Not quite tall enough to reach comfortably over the top of the counter, I would stand on a short stool and dip the cup measure into a crinkling bag of silky white powder. I would perform my tasks seriously, with a precision that exasperated my sister, three years older but infinitely less patient. Once each cup of flour was flawless, smoothed delicately with the back of my index finger and then placed, not dumped, in the bottom of the bowl, I would repear the process with teaspoons of salt and baking soda before coaxing them together with a wooden spoon. Finished, I would look at my sister eagerly, awaiting more orders.

“Butter,” Cecily would demand, pouring lumpy, uneven cups of white and brown sugar into a separate bowl. I would sprint for the butter, giving each stick a gentle squeeze to determine its softness before laying them atop of the mountain of sugar. Greasy fingers wiped on hand-me-down jeans, I would step back to watch as she assembled our handheld mixer with certitude, a defiant child turned quick-tempered preteen. A confident hand steadying the bowl, she would whip the butter and sugar into fluffy, pale yellow submission.

“Eggs,” she would say, arm extended and palm up. I obeyed; handling the eggs required a sureness I didn’t have as a dreamy child. When I cracked an egg, I tapped its thin shell softly against the side of the bowl, leaning in close to watch with fascination as a web of wispy fractures destroyed its smoothness. I would press my thumbs into the compromised area and pull the two halves away from each other slowly, watching the white, inner membrane tear and the gooey insides spill out. This approach maddened my sister and left flakes of broken shell in the batter. So I left this part of the process to Cecily, who would crack the eggs with a single, decisive thwack and throw the empty shells over her shoulder into the sink. She picked up the wooden spoon automatically and then hesitated, turning to me.

“Do you want to stir, Liv?” She would ask in a softer voice, offering the spoon to me. I stirred the sticky batter while she added the vanilla, the flour mixture, and the chocolate chips until the dough was too stiff for me to mix, at which point she gently took the spoon from my hand and finished the job.

Trays lined and oven heated, my sister held out a protective arm.

“Stay back,” Cecily would warn as she opened the oven, a wave of dry heat smacking our faces.

Around the same time that this baking ritual took shape, Cecily and I began watching Friends. When we discovered the sitcom, the pilot of which had aired the year I was born, it was in its final season. We burned through hundreds of episodes in a matter of months. Stumbling across an episode neither of us had seen became more and more rare. Before long, we knew every line by heart, anticipating jokes and giggling a few seconds before the punch line.

These two rituals quickly became intertwined. As soon as the cookies were in the oven and the timer set to fourteen minutes, we would disappear down the basement stairs and into a cramped television room. An oversized green couch with corduroy cushions left ribbed imprints on our cheeks as Cecily flicked on the TV and scrolled through endless variations of “The One Where…”

“The One Where No One’s Ready?” I suggested.

“Is that the one where Joey takes Chandler’s chair?”

I nodded vigorously. “Could I be wearing anymore clothes?” I said in my lowest voice, impersonating Joey impersonating Chandler.

Cecily snickered, and then widened her eyes in an exaggerated concern. “You were gonna drink the fat,” Cecily whined, a spot-on Rachel.

I’ll be there for you, when the rain starts to pour. I’ll be there for you, like I’ve been there before. I’ll be there for you, ‘cause you’re there for me too.

We laughed at jokes we had heard countless times, sexual innuendos and dated references sailing over our heads, until the timer broke our collective trance. We pressed pause and sprinted back up the stairs to the kitchen. We transferred them to wire racks to cool while we finished the second half of the episode in our cave.

We made so many cookies during this time that our father had to freeze whole batches while we ate our way through last week’s leftovers. I grew accustomed to packing frozen cookies in my lunch box, secure in the knowledge that they would thaw by lunchtime.

Only three years apart, our childhood was all shared bedrooms and matching raincoats. We had never been overtly affectionate with one another; we didn’t hold hands or make friendship bracelets. Instead, our relationship was a tacit understanding that needed very little maintenance or verbal affirmation. I was devoted to her fully, idolized her, emulated her, and expected nothing in return except the privilege of being in her presence, the simple joy of her attention. And she was devoted to me in her older sister way, braiding my hair for school and letting me climb into her bed when I had nightmares. We spent many years like this, but when she entered high school, things changed. She began to disappear from me into the murky depths of adolescence, leaving me, perpetually three years behind, wondering where she had gone.

It was around this time that we stopped baking together. The change didn’t happen all at once, but rather it was a gradual, nearly undetectable shift. Unable to resist a new gadget, our father surprised us one night with a powerful stand-up mixer that cut the cookie preparation time in half. When we arrived at our father’s house, we would each disappear into our separate rooms; homework, instead of baking, preoccupied us on Monday nights. Our freezer, once overflowing with dozens of frozen cookies, began to empty.

During these years Cecily changed too. Her moods, which had always been unpredictable, would darken with hardly any warning, and soon the bad moods vastly outnumbered the good ones. She fought with my parents bitterly and, when she wasn’t ignoring me entirely, threw snide, taunting comments. I learned to keep my distance from her, tiptoeing around her volatile temper. Either unaware of or unwilling to accept the slow decomposition of his daughters’ relationship, our father continued to arrange the cookie ingredients on the counter for us, where they would lay untouched in hopeful lines. Two sticks of butter would melt on the stovetop every Monday night, until our father, defeated, put them away.

Two winters came and went before my sister began to thaw. Just as gradually and inexplicably as she had disappeared from me, she began to reappear. I entered ninth grade at the same high school where Cecily was a senior. She drove me to and from school everyday, rolling down all the windows and blasting Kanye West and Taylor Swift through quiet, Cambridge neighborhoods. At first, I just giggled nervously as Cecily tossed her head back and belted out the lyrics, but before long the dynamic between us started to shift. By October I sang just as loud as she did as I dangled my arm out of the passenger seat window, feeling the crisp, fall air whip through my fingers and watching red and orange leaves form a rusty blur before my eyes.

We had always been sisters, but that year we became friends. On lazy Saturday mornings, she would wake up and climb into my bed, where we would watch pirated episodes of Friends on my laptop. On Saturday nights, I would help her pick outfits for parties I was not invited to, feeling important when she took my advice. The night before she left for college, I slept in her bed, and she whispered to me that she was scared. At the airport she boarded a flight to California, and I cried in the backseat of my mother’s car as we drove home.

The first winter after Cecily went to college, a new culinary tradition was born. A few days before Christmas, Cecily and I walked into our father’s kitchen to find a small glossy book on the countertop. Macarons. Inside the book were painstakingly precise recipes for how to create the delicate French cookies. Our father had become infatuated with them while in Paris on business, and had decided that we would learn how to make them. He went to remote specialty stores to procure the ultra-granulated cane sugar, almond flour, and a small baking scale, which he had arranged neatly on the counter next to the recipe book.

On Christmas Eve, we awoke early to prepare. We pored over the recipes, studied the pages of common mistakes and helpful tips, and made note of every last detail. Use the wrong kind of sugar and your macarons will fail to form their characteristic feet. Beat the egg whites too quickly and the cookies will be thick and dense instead of light and airy. Let the batter stand too long and the shells will crack, too little and they won’t hold their shape. Baking macarons required a level of precision that our childhood ritual had lacked.

“Shit,” I heard my sister hiss under her breath from across the kitchen. She was trying to separate the eggs for the meringue-like shells, but had accidentally ripped the yolk’s delicate membrane. I approached her tentatively.

“Here, let me show you,” I said, throwing away the ruined batch of whites and rinsing out the bowl.

“You can’t smash the egg on the side of the bowl or you’ll break the yolk,” I explained, taking a fresh egg from the carton. I could sense that Cecily bristled slightly at being told what to do, but she nodded for me to continue.

“See, like this.” I tapped the egg softly against the bowl to split the shell, and then poured it into my hand, yolk and all, into my cupped palm. I gently passed the slimy yellow-orange orb from hand to hand, allowing the egg whites to drip from my slightly parted fingers.

“Got it?” I asked, tossing the yolk in the sink. Cecily let out a non-committal grunt and gingerly picked up another egg, and broke the shell with noticeable restraint.

We worked slowly and methodically throughout the day, the oven filling the kitchen with a dry heat as powdery snow dusted the street outside. At the end of the day, coated in sweat and sugar, we stared at our finished product. They were cracked and misshapen with filling that seeped out the sides; they looked nothing like the perfect, pastel masterpieces on the cover of the book. That night, we wrote in the recipe book’s margins everything we did wrong, and vowed to improve our technique next time.

And every Christmas Eve, we’ve gotten (barely any) better.