Chocolate depression cake is a moist chocolate sheet cake that was popular during the depression - due to the cake containing no eggs, dairy or butter!
In a medium-sized mixing bowl, combine the 1 ½ cups all-purpose flour, ½ teaspoon salt, 4 Tablespoons cocoa powder, 1 cup granulated sugar and 1 teaspoon baking soda; whisk until all combined.
In a large liquid measuring cup, combine the ½ cup vegetable oil, 1 cup cold water, 1 teaspoon vanilla extract and 1 Tablespoon white vinegar
Mix into dry ingredients and whisk until smooth.
Pour into a greased 8” square baking pan and bake at 325°F for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
Cool cake completely before frosting.
For the frosting:
Combine all ingredients for the frosting (3 Tablespoons unsalted butter,, 2 Tablespoons cocoa powder,¼ teaspoon salt, ½ teaspoon vanilla extract,2 Tablespoons evaporated milk) in a medium-sized mixing bowl and beat until smooth. Spread onto cooled cake.
Notes
You can easily double this recipe; use a standard 9" x 13" baking pan and bake for the same amount of time
To keep this cake dairy free, omit the chocolate frosting. Top the cake with a dusting of powdered sugar instead
Store in an airtight container up to 3 days or freeze up to 3 months