In a large bowl combine butter, shortening, and sugar. Beat until fluffy (I use my stand mixer, but an electric hand mixer works great too).
Add egg, vanilla and almond extract. Mix.
In a separate bowl, combine dry ingredients.
Slowly add dry ingredients to wet ingredients until a soft dough forms. Dough will be soft, but slightly crumbly.
Scrape dough out of the bowl with a rubber spatula and press dough onto an ungreased cookie sheet/baking pan (13" x 18").
Bake in oven at 350 degrees for 15-18 minutes.
Cool unfrosted bars completely.
Mix frosting ingredients together until fluffy. Frost cooled cookie bars in an even layer and add sprinkles.