Preheat oven to 375 degrees. Spray an 8 by 8-inch baking dish with non-stick cooking spray.

In a mixing bowl whisk together flour, cornmeal, baking powder, baking soda, salt, cinnamon, ginger, nutmeg and cloves for 20 seconds. Make a well in center of flour mixture then set aside.

In a separate mixing bowl, add brown sugar and break up sugar with fingertips until no clumps remain. Add in melted butter and pumpkin and whisk to combined.

Mix in sour cream and eggs until well blended. Pour mixture into well in flour mixture then fold with a rubber spatula just until combined and no streaks of flour remain.

Pour batter into prepared pan. Spread batter into an even layer.

Bake in preheated oven until toothpick inserted into center comes out free of batter, about 25 - 30 minutes. Cool slightly on a wire rack then cut into squares.

In a mixing bowl (or using a stand mixer) whip butter with an electric hand mixer until smooth.

Add in honey, powdered sugar and cinnamon and mix on low speed until combined, then increase to high speed and whip until light and fluffy, about 2 - 3 minutes.