Cookies
1/3 cup mashed ripe banana
1/3 cup butter and margarine, softened
2 oz cream cheese, softened (1/4 cup)
1 teaspoon vanilla
1 egg
1 pouch (1 lb 1.5 oz) Betty Crocker® sugar cookie mix
2 tablespoons Gold Medal® all-purpose flour
Filling
3 cups powdered sugar
1/2 cup butter or margarine, softened
1/3 cup Yoplait® Thick & Creamy banana yogurt
Topping
1 tablespoon powdered sugar

1. Heat oven to 375°F. In large bowl, stir banana, 1/3 cup butter, the cream cheese, vanilla and egg until well blended. Add cookie mix and flour; stir until soft dough forms.
2. With medium cookie scoop or by heaping tablespoonfuls, scoop dough 2 inches apart onto ungreased cookie sheets.
3. Bake 7 to 9 minutes or until edges begin to brown. Cool 2 minutes; remove from cookie sheets to cooling rack. Cool completely, about 30 minutes.
4. In large bowl, beat filling ingredients with electric mixer on low speed until blended. Beat on high speed about 2 minutes or until lightly and fluffy.
5. To make each sandwich cookie, spread about 1 tablespoon filling on bottoms of 16 cookies. Top each with one of the remaining cookies; gently press cookies together.
6. Sprinkle tops of sandwich cookies with powdered sugar. Store between sheets of waxed paper in tightly covered container in refrigerator.
High Altitude (3500-6500 ft): Increase flour to 1/4 cup.

Source: bettycrocker.com