Preheat oven to 300oF (150oC).
Line baking sheet with parchment paper or baking mat.
Melt unsalted butter and set aside.
In the mixing bowl whisk together flour, sugar, salt and pumpkin spice powder.
Add melted butter and mix with the fork or spatula until clumbs form.
Transfer mixture into prepared baking sheet.
Bake for 10-15 minutes. Baked crumbs should be light brown.
Let crumbs cool completely before using for desserts.