Grease 9-inch round cake pan with shortening and dust with cocoa.
Beat low carb sweetener into butter until light and fluffy. Add eggs, one at a time. Mix in vanilla extract.
In separate bowl, combine dry ingredients (almond flour, coconut flour, cocoa, baking powder, and salt).
Beat in half the dry mixture into wet mixture.
Then beat in half the sour cream (or yogurt), then the rest of the dry mixture, and then the rest of the sour cream.
Mix in red food coloring (you will need quite a bit for a red color, ¼ teaspoon of gel food dye works well).
Pour batter into prepared pan.
Bake at 350 degrees F for about 25-30 min.
Remove from pan and allow to cool.
To make frosting, beat together cream cheese and butter until well combined.
Beat in sweetener until fluffy. Mix in vanilla extract.
Spread frosting evenly over the top and sides of the cake. Sprinkle on finely chopped pecans if desired for garnish.