Ingredients

• 1/2 cup butter, softened
• 1/2 cup shortening
• 2 cups sugar
• 1 tsp cream of tartar
• 1 tsp baking soda
• 1/8 tsp salt
• 3 egg yolks
• 1/2 tsp vanilla extract
• 1 3/4 cups flour
• Colored Sugar (optional)

Directions

1. Preheat oven to 300 degrees. In a large mixing bowl, combine butter and shortening with electric mixer on medium high speed for 30 seconds. Add sugar, baking soda, cream of tartar, and salt. Beat until combined, scraping bowl.
2. Beat in egg yolks and vanilla, mixing until combined. Add flour and beat to combine.
3. Shape dough into 1 inch balls, roll in colored sugar. Place balls on parchment lined cookie sheet 2 inches apart. Bake in preheated oven 12 to 14 minutes, or until set. Do not let the edges brown. Cool on cookie sheet for 1 minute and transfer to wire rack.

Makes 48 cookies.