Preheat oven to 325 degrees F. Coat bottom and sides of a loaf pan with cooking spray.
Cream butter and sugar; add eggs one at a time, beating with each addition. Sift flour, flax meal, baking powder, salt, and cocoa together (then, according to Mawmaw’s recipe you need to sift 3 more times. I don’t normally do this with cakes, but did this time).
Add flour and milk to creamed butter alternately, beginning and ending with flour and beating after each addition. Add vanilla. Beat on medium-low for 2 minutes, stopping to scrape bowl down as needed. Spoon batter into prepared pan.
Bake at 325 degrees F for 50 to 60 minutes or until wooden pick inserted in center comes out clean. Remove from oven and let cool in pan on a wire rack 10 to 15 minutes.
Remove cake from pan. Carefully spoon frosting by heaping tablespoons over top of cake, gently smoothing to edges. Let frosting melt over top and sides of cake creating a thin icing.