Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x13 inch pan.
In a large bowl, cream together the butter and sugars. Beat in the eggs one at a time, then stir in the vanilla.
Combine the flour, baking powder, baking soda and salt; stir into the batter until just blended. Fold in the sour cream, walnuts, and 1 cup of the gumdrops.
Spread the batter evenly into the prepared pan. Sprinkle the remaining gumdrops over the top.
Bake for 25 to 30 minutes in the preheated oven, or until a toothpick inserted into the center of the cake comes out clean.
Interesting Facts
Gumdrops were first made in the 1800s in Germany.
Gumdrops have a long shelf life and can be eaten up to a year after they are made.
Gumdrops are a popular topping for cakes and other desserts.