Preparation

• Heat oven to 350 degrees. Grease the bottom and sides of a 13x9 inch baking pan.
• Place the cake mix, oil, eggs, sour cream, pumpkin and pumpkin pie spice in a large bowl. Beat with an electric mixer on medium speed about 2 minutes until ingredients are just incorporated.
• Measure out 2 cups of batter, place the batter onto the bottom of your prepared pan.
• In a small bowl combine the walnuts with the brown sugar. Toss to combine. Sprinkle evenly over the cake batter.
• Spoon the remaining batter evenly over the filling. Using a spatula, carefully spread batter over the filling to the edges of the pan.
• Place in the oven and bake about 35 - 40 minutes or until a toothpick inserted comes out clean. Remove the pan to a cooling rack.
• Make the glaze: Place the powdered sugar, milk and vanilla in a medium bowl. Whisk to combine. Pour the glaze over the top of the hot cake, using a spatula to cover the entire cake with glaze.
• Cool the cake completely before serving.