Preheat the oven to 375°F. Line two baking sheets with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, add the butter, cane sugar, light brown sugar, and vanilla extract. Mix on low until combined and there are no chunks of butter.
Add the milk, flour, cocoa powder, baking powder, and sea salt into a bowl and add into the butter mixture. Mix on low until combined. Then add the dark chocolate chips and mix to combine.
Using your hands, form the cookie dough into 16 balls and place on the prepared baking sheet. Flatten them so they are disks that are about 2-inches in diameter.
Bake for 12 to 14 minutes or until the middle looks cracked and the edges look dry. Sprinkle with cane sugar immediately after coming out of the oven. Allow to cool completely on the baking sheets.
Store in an airtight container for up to 7 days, or in the freezer for longer.
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Notes
Gluten Free — Replace the all purpose flour with 205 grams (1 ¼ cups plus 1 tablespoon) gluten free flour blend.High Altitude — Baked 375°F 11 to 13 minutes or until the middle looks cracked and the edges look dry.