1-Getting Started: First, preheat your oven to 350°F and line two 9-inch square baking pans with parchment paper, leaving an overhang for easy lifting. Gather all ingredients and measure them precisely to avoid any mishaps.

2-Mixing and Baking: Melt the butter in a microwave-safe bowl or on the stove, then whisk in the sugar until combined. Add the eggs and vanilla extract, and whisk again to create a smooth mixture. Fold in the cocoa powder, flour, salt, and baking powder; the batter will be thick and total about 4 cups.

3-Mixing and Baking: Spread half of the batter evenly into one prepared pan and place a piece of parchment directly on top to keep it flat. Bake for 15-16 minutes to slightly under-bake for softness, then let it cool for 5 minutes. Lift the warmed brownie sheet out of the pan and remove the top parchment. Repeat with the remaining batter in the second pan, baking for another 15-16 minutes and cooling for 15 minutes.

4-Assembling and Freezing: While the brownies cool, soften the ice cream. Spread it evenly over the warm brownie sheet still in the pan, then place the first brownie sheet on top of the ice cream layer and gently press down. Cover tightly with foil or plastic wrap and freeze for 12 to 18 hours to achieve the best slicing consistency.

5-Assembling and Freezing: Remove from the freezer, lift out using the parchment overhang, and cut into 8-12 squares or rectangles with a sharp knife. For dietary adaptations, use vegan or gluten-free ingredients at each step to keep the dessert’s integrity intact.