Red Velvet Whoppie Pies - the alternative to the cake

Birthday cake time! I love Red Velvet Cake. But one whole cake for two people who shouldn't eat that much sweets at a time when we're surrounded by chocolates and candies already? So I "downscaled" the  cake idea to Whoppie Pies. Smaller portions and you can freeze them and take them out if needed. The idea for Red Velvet Whoppie Pies isn't mine but the following recipe is a conglomerate of about three I found in the internet adapted to my taste and since the first filling came out much too runny I changed that completely. Since there's only filling and no icing I allowed a bit more butter in order to make it easier to spread on and stick two half pies together.

1 1/4 cup flour
1/4 t. baking powder
1/4 t. salt
1 T. cocoa powder
1/2 t. baking soda

1/4 cup butter (57g for those who don't have cups indicated on the package)
3/4 cup sugar
1 large egg
1/2 cup buttermilk
1 t. - 1T. red food coloring (depending on how concentrated your coloring is)
1/2 t. lemon juice (or white vinegar)

Mix the dry ingredients in a bowl. Cream butter and sugar until fluffy, add the egg and buttermilk, beat. Add buttermilk, lemon and food coloring. Mix into the dry ingredients, beat the whole thing into a homogenous batter.
Take a tablespoon or a small ice scoop and drop heaps of batter on a baking tray you lined with a baking sheet. Space apart approx. 5cm! Makes 16-20 heaps.
Bake at 190° for approx. 10min. Edges should be slightly browned.

Filling:
1/2 cup butter (or 110g)
2 T. cream cheese
1 1/2 cup confectioner's sugar
1/2 t. vanilla extract (or vanilla sugar)

Mash the butter with a fork until softened, add cream cheese, confectioner's sugar and vanilla. Mix into a creamy filling. Take one of your "buns", spread a good teaspoon full onto the flat side, press a second "bun" with the flat side on it. Looks like a burger with the colors the wrong way 'round. :-)
Put in the fridge to let the filling set.

I mixed some confectioner's sugar with a bit of lemon juice (water would do as well) into a stiff mixture. I scraped the mixture into a little plastic bag, cut off one corner and wrote a letter onto each "burger" to make a HAPPY B-DAY. You could also use left over filling to spread on the tops and add some sprinkles or ... oh, get creative yourself! :-D