Allow butter, egg and yolks to stand at room temperature for 30 minutes or until butter is soft.
Prepare muffin pan by lining with cupcake liners.
Preheat oven to 350 degrees.
In a medium mixing bowl combine flour, salt and baking powder.
In a large mixing bowl beat butter with an electric mixer on medium to high speed for 1 minute.
Add sugar, beating for one minute on medium-high speed.
Add egg, egg yolks and vanilla.
Beat until combined.
Add the four mixture alternately with the heavy whipping cream, ending with whipping cream.
Batter will be thick.
Use two small bowls and spoon out a little bit of batter into each bowl. About 1/2 cup.
Add food coloring until desired color is reached. Should only need a few drops.
Once color is reached spoon one color at a time into the muffin cups.
I did orange, yellow, orange.
Bake for 18-20 minutes or until toothpick inserted in the center comes out clean.
Allow to cool in pan before placing in wire rack to cool completely.