Follow these simple steps to create your delicious Pumpkin Crumb Cake Muffins:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Line a muffin tin with paper liners or grease it lightly.
2. Mix Dry Ingredients: In a large mixing bowl, whisk together the flour, granulated sugar, brown sugar, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger until well combined.
3. Combine Wet Ingredients: In a separate bowl, mix the vegetable oil, eggs, pumpkin puree, and vanilla extract until smooth.
4. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients, mixing just until combined. Be careful not to overmix.
5. Prepare the Crumb Topping: In a small bowl, combine the flour, brown sugar, cubed butter, and cinnamon. Use your fingers or a pastry cutter to mix until crumbly.
6. Fill Muffin Cups: Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full.
7. Add Topping: Sprinkle the crumb topping generously over each muffin.
8. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
9. Cool: Once baked, remove the muffins from the oven and let them cool in the tin for about 10 minutes. Transfer them to a wire rack to cool completely.

These step-by-step instructions will help you create Pumpkin Crumb Cake Muffins that are sure to impress!