World's Best Pumpkin Cookies

(originally found here)
1/2 c. butter
1/4 c. brown sugar
1/4 c. white sugar
1/2 can pumpkin (or more)
1 sm. egg
1 tsp. vanilla
1 c. flour
1/2 tsp. soda
1/2 tsp. baking powder
1/2 tsp. cinnamon
1 tsp. salt

Cream sugars and butter. Add pumpkin, egg, and vanilla. Add remaining ingredients. Drop spoonfuls onto non-greased cookie sheet. Cook at 350* for 10 to 12 minutes.

Frosting
Boil 3 TBLS butter and 1/2 cup brown sugar until mostly smooth. (Approx. 2 to 3 min.) Cool and add 1/4 cup milk and 2 cups powdered sugar or until desired consistency, and whip with hand mixer until smooth. Spread onto cookies.