Preheat oven to 350 degrees.

Grease and flour three 8-inch cake pans, then line the bottom with a piece of parchment paper cut in a circle to fit. Set aside.

Add the beer and butter to a large, heavy bottom saucepan. Warm on medium until the butter melts then remove from the heat and gently whisk in the cocoa powder until smooth. Cool to room temperature.

In a large mixing bowl combine the flour, sugar, baking powder and salt. Whisk until blended and set aside.

In a separate large mixing bowl beat together the eggs and sour cream.

Gently add the cocoa mixture and blend on low until combined.

Add the flour mixture on low speed, scraping down the sides as needed. Mix on medium for 1 minutes.

Divide the batter between the three prepared cake pans. If you have a kitchen scale, each one should weigh a little over 2 pounds. Bake for 35 to 40 minutes or until a toothpick comes out almost clean, or at least not wet. Crumbs are okay. Do not over-bake.

Cool the layers on a rack for ten minutes, then remove the cake from the pans and continuing cooling on the wire rack until no longer warm.

Frost as desired and store leftovers in the refrigerator.