Jell-O Jewel Swirl Cookies

2 cups all-purpose flour
1/2 teaspoon baking soda
1/4 teaspoon salt
3/4 cup unsalted butter, softened
1/2 cup granulated sugar
1/2 cup sour cream
1 small box Jell-o (any flavor)

Cream butter and sugar together, then add sour cream. Add the dry ingredients. Blend well and chill 2 hours or overnight.

Divide dough in half and roll each into a rectangle. Brush rectangles with water and sprinkle each with 1/2 package Jell-O. Roll up. Chill for 1 to 2 hours.

Cut into slices. Put on greased cookie sheets and bake at 350 degrees F for 10 to 12 minutes.