In the bowl of a stand mixer fitted with the paddle attachment, mix the flour, baking powder, sugars, and salt together, to disperse the powder, break up any lumps of sugar and distribute dry ingredients evenly.
Add the cold butter and coconut oil, and mix on low speed until the mixture resembles coarse sand, about 4 minutes. The coconut oil isn't specified as solid or liquid. I used it in solid form; it doesn’t break down very well, so break it into smaller pieces, maybe even grate it into the dry ingredients.
Add the eggs, vanilla, and sprinkles. Mix on low speed until the eggs have been completely incorporated and you have a thick dough. Do not over beat.
Preheat your oven to 375°F (190°C). Line two baking pan with parchment paper.
Use a spoon, I use an ice cream scoop, to portion the dough into twelve balls, and roll them in granulated sugar, then in confectioners' sugar. Use a scale to weigh dough and portion equally.
Transfer them to a pan, and freeze them for 30 minutes. Once they're chilled, roll each ball in confectioners' sugar once more.
Place the balls of dough on the parchment-lined sheet pans, six well-spaced cookies on each sheet. Press them gently to flatten slightly.
Bake for 10 minutes on the center rack of oven, rotate the pan, and bake for an additional 5 to 6 minutes, until the cookies are puffy and set at the edges.
The centers will look cooked, but when lightly touched on top, will have a slight puffy, squishy give. Eat them fresh, just after cooling.
Store cookies in a sealed container in the fridge. Warm them for 15 seconds in the microwave to refresh them before eating.