In a large bowl beat together the butter and sugar until it becomes a nice cream
Add eggs, one at a time, beating well after each addition.
In another bowl, combine the red pigment with cocoa until cocoa is completely dissolved. And add this to the butter mixture and stir.
Add to mixture alternately the flour and sour cream to the mixture, beginning and ending with the flour, beating slowly and thoroughly.
Add the vanilla extract and baking soda and mix well
Grease and alefroste a round cake tin diameter 23 cm.
Pour the cake mold and bake in a preheated oven at 180 degrees for about 30 minutes.
Allow the cake to cool and prepare the glaze. In a small saucepan, mix the flour with the milk adding milk slowly to avoid creating clots.
Cook over medium heat, stirring constantly, until the mixture resembles glue.
Allow to cool completely.
Beat together the butter, sugar and vanilla extract until fluffy.
Add the flour mixture to the cold-milk and beat on high speed until very fluffy.
Spread over cold cake.