Preheat the oven to 350°F. Prepare (butter & flour or spray with non-stick spray) two 8-inch round cake pans.
Sift together the flour, sugar, cocoa, baking soda, baking powder and salt in a large bowl. Set aside.
In a stand mixer add in the sour cream, vegetable oil and eggs. On low speed mix the ingredients together.
Gradually add the dry ingredients into the wet ingredients.
Beat on low until just combined, scraping down the edges as necessary. Be careful not to overmix.
Remove bowl from mixer and fold in the beer.
Divide the batter between the prepared pans and bake for 30 to 35 minutes, or until a cake tester comes out clean.
Cool the cakes in their pans for 10 minutes before carefully turning them out onto a cooling rack.