01 - Preheat oven to 350°F. Line an 8x8 inch baking pan with parchment paper, ensuring paper extends over 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, being careful not to overmix. Fold in the dark chocolate chips.
03 - Spread the brownie batter evenly across the bottom of the prepared pan, using a spatula to create a uniform layer.
04 - In a separate bowl, beat together softened vegan butter, brown sugar, and granulated sugar until light and fluffy, approximately 2 minutes. Add plant milk and vanilla extract, mixing well to incorporate.
05 - Add flour, baking soda, and salt to the butter mixture. Stir until just combined, avoiding overmixing. Fold in the chocolate chips until evenly distributed.
06 - Carefully spread the cookie dough over the brownie batter in an even layer. Lightly moisten hands or spatula with water to prevent sticking and achieve smooth coverage.
07 - Bake for 30-35 minutes until the top is golden brown. A toothpick inserted into the center should emerge with a few moist crumbs attached, indicating fudgy texture.
08 - Allow the brookies to cool completely in the pan, approximately 1-2 hours. Use the parchment paper overhang to lift the dessert from the pan, then cut into 12 equal squares.