Do you need to change the recipe use butter instead of margarine?

- 1 cup margarine or butter, softened

- 1/2 cup sugar

- 1/4 cup firmly packed brown sugar

- 1 egg yolk

- 2 teaspoons vanilla extract

- 2 cups all-purpose flour

- 1 teaspoon baking powder

- 1 teaspoon salt

Instructions:

- Preheat oven to 375 degrees F (190 degrees C).

- Cream the butter or margarine and sugars until light and fluffy.

- Beat in the egg yolk, vanilla, flour, baking powder, and salt.

- Form dough into 1-inch balls and place 2 inches apart on ungreased baking sheets.

- Flatten each ball with a floured fork to make a crisscross pattern.

- Bake for 8-10 minutes or until edges are golden brown.

- Let cool for 2 minutes on baking sheets, then transfer to wire racks to cool completely.