For the Bars:
1 cup each granulated sugar
1 cup light brown sugar
1 cup canola oil
1 can pumpkin purée (15 oz.)
4 eggs, room temperature
1 Tbsp. vanilla extract
2 cups all purpose flour
2 tsp each baking powder and ground cinnamon
1 tsp each table salt and baking soda
1?2 tsp ground ginger
1/2 tsp cloves
1/2 tsp and nutmeg
For the white chocolate frosting:
4 oz. white bar chocolate, chopped
1 pkg cream cheese, softened
1 stick unsalted butter
1-1/2 cups sifted powdered sugar
1. Preheat oven to 350°. Coat an 11 1/2×16 1/2-inch baking sheet with nonstick spray.
For the bars, whisk together granulated sugar, brown sugar, oil, pumpkin purée, eggs, and vanilla in a large bowl.
2.Sift flour, baking powder, cinnamon, salt, baking soda, ginger, cloves, and nutmeg into pumpkin mixture. Whisk mixture into wet ingredients until combined. Spread batter onto prepared baking sheet. Bake until toothpick inserted in center comes out clean, about 20 minutes. Transfer pan to a rack and cool completely before frosting.
3. For the frosting, melt white chocolate in a microwave on high, 1–2 minutes; stir until smooth.
4. Beat cream cheese and butter with a mixer on high speed until smooth. Add melted chocolate and beat to combine. Add powdered sugar and beat on low speed until smooth. Spread frosting over cooled bars, top with garnish, see left, and cut into bars.