1-First Step: Preheat your oven to 350°F (175°C) and grease a 9×9 inch baking pan with a vegan butter alternative to accommodate dietary preferences.

2-Second Step: In a mixing bowl, sift together the all-purpose flour, cocoa powder, baking powder, and salt to ensure even distribution.

3-Third Step: In a separate bowl, combine sugar, unsweetened applesauce, vinegar, red food coloring, and vanilla extract, mixing well to create the wet base.

4-Fourth Step: Gradually incorporate the dry ingredients into the wet mixture, stirring gently until a smooth batter forms; for gluten-free needs, ensure the flour blend is properly mixed.

5-Fifth Step: Pour the batter evenly into the prepared baking pan, spreading it with a spatula for uniform thickness.

6-Sixth Step: Bake in the preheated oven for 25-30 minutes, checking doneness by inserting a toothpick that should come out clean or with a few moist crumbs.

7-Seventh Step: Remove from oven and allow to cool completely in the pan on a wire rack before cutting to maintain structure.

8-Final Step: Slice into square portions and serve; for make-ahead or meal prep, store appropriately using recommended refrigeration or freezing methods.