Preheat the oven to 350°. Spray a 9-inch round baking pan (I used a spring form for prettier serving) with nonstick cooking spray.
In the bowl of a food processor, combine the flour, brown sugar, and butter. Pulse until coarse crumbs form.
Remove 1 cup mixture and set it aside.
Add the baking powder, salt, cinnamon, egg, pumpkin, and milk to the remaining flour mixture. Blend until smooth.
Pour the batter into the prepared pan.
In a small mixing bowl combine the reserved crumb mixture and the pepitas. Sprinkle this crumb topping over the batter.
Bake the coffeecake for 40 minutes or until a tester comes out clean.
Cool slightly before serving. Serve warm or at room temperature.
Promptly store leftovers in an airtight container, for up to 3 days.Nutritional values are approximate and based on 1/12 the cake.To make as a mix: Take a large ziptop bag or container and label it with the wet ingredients and the baking instructions. Measure out the flour and sugar into the bag. Measure out baking soda, salt, and cinnamon into a smaller bag. Measure out the pipits into a third bag. Seal and store the bags together until ready to use.