The house smells of toasted pecans and butter. Outside, the sky hangs heavy and gray with cold – perfect for baking in a warm, well-lit kitchen. In one hour, I will leave to pick up my son from preschool and I will carry his wheelchair and his then-five-year-old self up the stairs and into this homey scene.

“The cookies are nothing special,” I will say if anyone asks – my polite way of not giving away the recipe. It’s been in the family for generations, originating with my grandmother who refused to use a food processor to dice the nuts into tiny minced bits. She toasted and then sliced every one by hand. If she were still alive, she’d pretend not to see the bags of pre-chopped extra fine pecans I’ve stashed in my pantry behind the olive oil. But my son doesn’t know the difference.

Thumbprint cookies are a universal treat and everybody has their own version. Nuts or no. Sweet or buttery. Chocolate, jam, lemon curd, or icing in the little doughy center. It’s a particular palate pattern that’s just as good as any Myers-Briggs test to define a person.

The family recipe is written in green in my grandmother’s looping cursive in the upper left-hand corner of a Methodist church cookbook that has long lost its cover. This single stained page is now protected in the confines of a lime green binder that is my mishmash of “family recipes,” i.e. the ones you can’t pin on Pinterest.

As a child, the thumbprinting was my job. I would stand on a stool next to my mother, who rolled out the sticky dough with buttered hands, placing the perfect-sized mounds in parallel lines down the baking sheet. I would stick one thumb straight down and wiggle it around a little (at age eight, your thumbs are still too small to make a decent divot without a little wiggling) and then we’d slide them in the oven and wait. A low and slow bake was the key to success.

The cookies themselves are incredibly simple and come out pale and just a little gold on the edges. They are buttery with something sweet underneath – the powdered sugared kiss at the end. You could eat them plain with a good cup of coffee, but it would leave the little indentation in the center bereft.

I use spray-can icing because it’s my son’s favorite and I am forever subject to his taste profile. However, I’ve found it suits just about anybody. Yellow for spring. Blue for birthdays. White for wedding showers. They are the cookie for all occasions. Today they will be red and green. Today we are celebrating the holidays in his particular way. He’s never cared about the twinkle lights or the caroling or even the presents. These cookies are Christmas for him.

By the time we get back from school today, they will be cooled just enough to ice and eat. He will get the inaugural bite. This is how I sneak into his world – a world of limited language and foods which has been a slow experiment in itself.

If left to his own devices, he tends to eat everything like a baby bird, swallowing it whole so you can see it slide down his gullet. “Crunch, crunch, crunch,” I would say in feeding therapy while he practiced gnawing on a Gerber cookie or Cheerio.

These cookies were the first homemade food he learned to love. Seeing my grandmother’s scrawled handwriting in my mind’s-eye, I would bake them from memory and then we would sit at his tray and eat them together. They were the way to his little boy-heart. From the first slightly soft and crunchy bite, he would grin and chomp and I would clap and lick icing off my fingers.

“More,” he would sign, until neither of us could possibly stomach another.

On this chilly afternoon as I crouch by the oven and watch the rounded edges take on their ochre glow, I can already see the evening unfold. He will laugh when I roll him past the cookies lined up like dominoes on the counter and he will clap at the first “pop!” of the icing spurting into the sink where I practice a squirt or two. Then he will not wait until I’ve finished more than one before wheeling over and holding out a hand. We will ice and eat and ice and eat until our tongues are red and green. This is how our two worlds, so often separated by silence, will come together.