Using Mixer cream butter and shortening until light and fluffy (roughly 2 minutes)
Add sugar and mix until fluffy again
Add eggs, vanilla and sour cream and mix thoroughly
Add flour, baking powder and salt and mix until completely combined
Divide dough into three pieces and wrap in plastic
Refrigerate for at least 2 hours (we left ours overnight)
To color the cookie dough: Place dough ball back in the mixer, added the food coloring and briefly mixed the dough on a low speed. (You don’t want to over-mix the dough so only mix it enough to get the dough the color you want.)
To get the pretty marble effect on the cookies: roll nine small balls of cookie dough in each of the three colors, each ball should be about the size of a large walnut.
Take the green dough balls and arrange them on the rolling surface.
Then randomly add in the white dough balls.
Finally add in the red dough balls.
Use your hands to press together the dough balls into a circle.
Use your rolling pin to roll out the dough until it is about 1/4″ thick, depending on how thick you want your cookie to be
Now arrange your cookies cutters on the rolled out dough so that the cut-out cookie will have all three colors on dough in the shape.
Cut out desired shapes and move to a parchment paper covered cookie sheet, leaving 1 inch between cookies
Bake in a 375 degree oven for 8-10 minutes, edges should be just slightly brown
Immediately move to a wire rack and cool completely