Pumpkin Pie Cake

INGREDIENTS

• Cooking spray
• 2 tablespoons all-purpose flour
• 1 cup granulated sugar
• 1/2 cup packed brown sugar
• 1/4 cup canola oil
• 1/2 cup egg substitute
• 2 large eggs
• 1 (15-ounce) can unsweetened pumpkin
• 2 cups all-purpose flour (about 9 ounces)
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 2 teaspoons pumpkin-pie spice
• 1/2 teaspoon salt
• 2 tablespoons butter, softened
• 1 (8-ounce) package 1/3-less-fat cream cheese
• 3 cups powdered sugar
• 2 teaspoons fresh orange juice
• 1/4 cup chopped pecans, toasted
• Orange slices (optional)