01 - Preheat your oven to 350°F. Line an 8x8 inch baking pan with parchment paper, leaving overhang on sides for easy removal.
02 - In a medium bowl, whisk together flour, cocoa powder, brown sugar, baking powder, and salt until well combined. Add melted coconut oil or vegan butter, plant milk, and vanilla extract. Mix until just combined. Fold in 1/2 cup vegan dark chocolate chips.
03 - Press the brownie batter evenly into the bottom of the prepared pan using a spatula or offset spatula.
04 - In a separate bowl, cream together softened vegan butter, brown sugar, and granulated sugar until light and fluffy, about 2 minutes. Add plant milk and vanilla extract; mix well. Gradually add flour, baking soda, and salt, stirring until just combined. Fold in 3/4 cup vegan chocolate chips.
05 - Carefully spread the cookie dough evenly over the brownie batter. Lightly wet your hands or spatula with water to prevent sticking and smooth the top.
06 - Bake for 30-35 minutes until the top is golden brown and a toothpick inserted in the center comes out with a few moist crumbs. The edges should be set but the center slightly soft.
07 - Allow the brookies to cool completely in the pan, about 1-2 hours. Lift from pan using parchment overhang and slice into 12 equal squares.