Preheat oven to 350 degrees F.

Grease, spray with baking spray, or line 2 dozen muffin cups with paper liners.

In a large bowl combine 3 cups flour, cinnamon, nutmeg, cloves, allspice, baking soda, baking powder, and salt together.

In a separate large bowl, whisk together pumpkin puree, 1 cup brown sugar, 1 cup white sugar, vegetable oil, applesauce, eggs, and vanilla extract together.

Stir flour mixture into pumpkin mixture; mix well.

Using a fork, combine the flour, sugar, walnuts, butter, and cinnamon for the streusel topping.

Pour the batter into the prepared muffin tin; and sprinkle each muffin with streusel topping.

Bake in the preheated oven for 20 to 30 minutes, or until a toothpick inserted in the center of a muffin comes out clean.

While the muffins are cooling, add the white chocolate chips and shortening in the top of a double boiler and heat over low heat. Stir until the white chocolate is melted. Then immediately drizzle the white chocolate over the muffins and serve.