Chocolate Cake

This is my favorite chocolate cake recipe. (Minus German Chocolate cake, but that's something else entirely.) It's really good. I found it in one of my Mom's Martha Stewart catalogs, but it was so long ago I don't know which one.

1 1/2 c butter, room temp.
3/4 c cocoa
2 1/4 c sugar
1 TBSP vanilla
4 large eggs
3 c sifted cake flour (I just use normal flour, unsifted :) )
1 tsp baking soda
1/2 tsp salt
1 c milk

Heat oven to 350deg. Grease 3 8" cake pans,and line bottoms with parchment.
1. Sift (again, I don't sift) cocoa into medium bowl. Whisk in 1 cup boiling water. Let cool.
2.In bowl of an electric mixer fitted with paddle attachment, cream butter until light. Gradually beat in sugar until fluffy. Beat in vanilla. Add eggs. Beat until smooth and fluffy.
3. In separate bowl, mix flour, baking soda, and salt. (I just mix it in the measuring cup so I don't have to wash another bowl.)
4. Whisk milk into chocolate mixture. Alternate adding the flour mixture and the cocoa mixture a little at a time, starting and ending with the flour mixture. Add to pans and bake 35-40 min. Invert pans onto wire rack to cool.