Prep the oven and pans: Heat the oven to 350°F (175°C). Line two baking sheets with parchment paper. This prevents sticking and helps even browning.

Mix dry ingredients: In a medium bowl, whisk almond flour, coconut flour, baking powder, and salt until no lumps remain.

Combine wet ingredients: In a large bowl, whisk melted butter and brown-style sweetener until smooth and glossy. Whisk in the egg, egg yolk, and vanilla until fully combined.

Bring it together: Add the dry mixture to the wet and stir with a spatula until a thick dough forms. Fold in the chocolate chips. If using espresso powder, add it with the dry mix.

Chill the dough: Cover and refrigerate for 20–30 minutes. Don’t skip this step—it prevents overspreading and keeps centers soft.

Form giant cookies: Scoop roughly 1/4 cup of dough per cookie (about 70–75 g). Roll into balls, then gently flatten to about 3/4 inch thick on the baking sheet, spacing them at least 3 inches apart. You should get 8–10 large cookies.

Bake: Bake for 11–14 minutes, rotating the pan halfway. The edges should be set and lightly golden, while the centers look slightly underbaked and puffy. They will continue to set as they cool.

Optional flair: Right out of the oven, sprinkle with flaky salt. For perfectly round edges, use a large round cookie cutter to “scoot” the cookies into shape while still warm.

Cool properly: Let cookies cool on the baking sheet for 10 minutes before transferring to a rack. This locks in the soft center without crumbling.