Adapted from my mother and The Kitchen Sink

Comparing my mom's recipe to the one Kristin used (which is from Cooking Light), the only real difference is that the Cooking Light version has about half the butter. Naturally, I opted for the "lighter" version. I find that white whole wheat flour hides well in a cake like this, so I used that instead of all-purpose flour. I also replaced the buttermilk with yogurt and it came out just fine.

This is half of the original recipe. Feel free to double it and bake in a 9x13 or 11x15 jelly roll pan.

Cake:
1 cup white whole wheat flour
1 cup sugar
1/2 tsp baking soda
pinch of salt
1/2 stick of butter (1/4 cup)
1/4 cup plus 2 tbsp water
2 tbsp cocoa powder
1/4 cup plain yogurt
1 tsp vanilla extract
1 large egg

Frosting:
3 tbsp butter
2 1/2 tbsp milk
2 tbsp cocoa powder
1 1/2 cups powdered sugar
1 tsp vanilla extract
chopped pecans

Preheat oven to 375°F. Grease and flour (or dust with cocoa powder) an 8x8-inch or 7x11-inch pan.

In a large bowl, whisk together flour, sugar, baking soda, and salt. In a small saucepan, combine butter, water, and cocoa powder. Heat to boiling, stirring well. Add to the flour mixture and beat well. In a small bowl, combine yogurt, vanilla, and egg. Add to the chocolate mixture and mix well. Pour into prepared pan and bake about 25 minutes, or until toothpick inserted in the center comes out clean. Let cool on wire rack.

While the cake is still hot, make the frosting. In a saucepan, combine butter, milk, and cocoa powder. Heat until bubbly, then remove from heat. Add powdered sugar and vanilla and mix well, until free of lumps. Pour over hot cake, then sprinkle with pecans. Let cool completely.