Step 1

Preheat oven to 350 F.

Step 2

In a small saucepan, use a whisk to stir together 1/3 cup flour and 1 cup water. Heat saucepan over medium heat, stirring frequently and cooking until mixture grows as thick as muffin batter (maybe a little thinner).

Step 3

Remove pan from heat and use a rubber spatula to scrape flour and water into a large mixing bowl. Set aside and let it cool completely.

Step 4

Place butter in the saucepan over medium-low heat. When the butter melts, remove the pan from the heat and stir in cocoa powder until the mixture is smooth with no lumps.

Step 5

Remove saucepan from heat and set aside.

Step 6

Add sugar, salt, and vanilla to the flour and water mixture in the large bowl. Beat or stir together until smooth.

Step 7

Add cocoa and butter to the mixing bowl and stir to combine.

Step 8

In a medium-sized mixing bowl, stir together flour and baking powder.

Step 9

Add flour mixture to the large mixing bowl and stir together.

Step 10

Pour batter into a greased 9x13-inch baking pan.

Step 11

Bake for 20-30 minutes, until a knife inserted in the center comes out clean. Do not overbake.

Step 12

Cool for 15-20 minutes, then cut into squares and serve.