• Preheat oven to 375°F. Line muffin pan with muffin papers.
• Mix together the flour, baking powder and cinnamon in a bowl and set aside.
• In the bowl of a stand mixer, cream together butter, sugar, vanilla and salt until light and fluffy. Beat in eggs one at time. Add the pumpkin purée and mix. Stir in the flour mixture with the milk, mixing until just incorporated.
• Fold in apples and walnuts.
• Using a scoop, ¾ fill the muffin cups. Sprinkle the tops with cinnamon crumble.

For the Cinnamon Crumble

• In a small bowl, combine butter, flour, sugar and cinnamon. Mix together using a fork until the crumble topping resembles rough sand.
• Bake in preheated oven for 30 minutes until tops are golden brown. They are ready when a skewer inserted comes out clean.
• Remove from pan and cool on a wire rack. Inspired by a recipe from AllRecipes