In a large mixing bowl, combine all-purpose flour, granulated sugar, unsweetened cocoa powder, baking powder, baking soda.
2½ cups all-purpose flour, 1 cup granulated sugar
Mix the dry ingredients thoroughly until well combined.
1½ teaspoon baking powder, 1½ teaspoon baking soda
Add blue gel food coloring (adjust for desired color) to the dry ingredients and mix well.
1 tablespoon blue gel food coloring
If preparing a cake mix for storage, vegetable shortening to the dry mix, using a pastry cutter or fork to cut it into the dry ingredients until it resembles coarse crumbs.
¼ cup vegetable shortening
Alternatively, if using the mix soon, omit the vegetable shortening for now.
Preheat your oven to 350°F (175°C).
Grease and flour cake pans or line a cupcake pan with liners.Pour the batter evenly into the prepared pans or liners. Bake at 350°F for 25-30 minutes for cakes or 15-20 minutes for cupcakes, or until a toothpick inserted into the center comes out clean.
Allow the cakes or cupcakes to cool completely before frosting and decorating.