Preheat your oven to 375°F (190°C). Grease an 8×8-inch baking dish with non-stick spray.

In a large mixing bowl, whisk together the flour, cornmeal, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, and cloves. Set aside. In another bowl, break up the brown sugar with your fingertips until smooth, then add the melted butter and pumpkin. Whisk until combined. Stir in the sour cream and eggs until fully mixed. Pour the pumpkin mixture into the well in the center of the dry ingredients and gently fold with a rubber spatula until just combined.

Pour the batter into the prepared pan, spreading it evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Let it cool slightly on a wire rack before cutting into squares.

In a mixing bowl (or stand mixer), whip the butter with an electric hand mixer until smooth. Add honey, powdered sugar, and cinnamon, mixing on low speed until combined. Increase the speed to high and whip for 2-3 minutes until light and fluffy.