From Mostly Edible Science by Andrew Schloss
1 cup flour
2 teaspoons baking powder
½ teaspoon baking soda
¼ teaspoon salt
1 cup granulated sugar, divided
Pinch of cinnamon
½ cup unsweetened cocoa powder, divided
½ cup milk
1 teaspoon vanilla extract
¼ cup vegetable oil
½ cup dark brown sugar
¼ cup fruit juice
¾ cup boiling water
Preheat the oven to 350℉. Grease an 8 inch square cake pan. In a large bowl stir together 1 cup flour, 2 teaspoons baking powder, ½ teaspoon baking soda, ¼ teaspoon salt, ¾ cup granulated sugar, pinch of cinnamon and ¼ cup cocoa powder.
Add ½ cup milk, 1 teaspoon vanilla extract, ¼ cup vegetable oil and stir.
Pour batter into cake pan and spread evenly. Sprinkle ½ cup brown sugar, ¼ cup granulated sugar and ¼ cup cocoa powder on top.
Pour in ¼ cup fruit juice and ¾ cup boiling water.
Baking for 30 minutes. Let pan cool on a wire rack for 10 minutes before serving.