01 - Preheat the oven to 375°F. Line two baking sheets with parchment paper.
02 - In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
03 - In a separate bowl, whisk together the granulated sugar, brown sugar, eggs, milk, sour cream or yogurt, melted butter, and vanilla extract until smooth.
04 - Add the wet ingredients to the dry ingredients and gently mix until just combined, avoiding overmixing.
05 - Carefully fold the semisweet chocolate chips into the batter.
06 - Using a large cookie scoop or 1/4 cup measure, drop mounds of batter onto the prepared baking sheets, spacing them approximately 2 inches apart.
07 - Bake for 11 to 13 minutes, or until the tops are set and a toothpick inserted into the center comes out with a few moist crumbs.
08 - Allow the muffin tops to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.