In a stand mixer, combine the butter and sugars and beat until fluffy and combined.
Beat in egg and extract(s) until well combined.
Add in the dry ingredients: flour, cocoa, baking soda, and salt.
Mix until just combined.
Finally, add in the milk and beat for a few seconds. Stop the mixer and use a spatula to fold in the strawberry pieces.
Scrape down the sides with the spatula. Put plastic wrap over the dough and press down over dough. Put in fridge for 2-24 hours.
Heat oven to 350 F. Line two baking sheets with parchment paper or silicone baking sheets.
Use a spoon to scoop 1" balls of dough onto the baking sheet, spaced 2-3" apart. Pick up each dough ball and press lightly into a plate with sprinkles, then set back onto the baking sheet, sprinkle side up.
Bake for 11-12 minutes and leave to cool on the sheet for a few minutes.