Adapted from Sally's Baking Addiction
Preheat oven to 425 degrees and muffin liners to a muffin pan.
Whisk together flour, baking soda, cinnamon, pumpkin pie spice and salt together and set aside.
Whisk together oil, sugar, brown sugar, pumpkin puree, eggs and milk in another bowl.
Add the wet ingredients to the dry ingredients and fold in mixture until just combined.
Scoop batter into muffin tins.
Mix together the flour, sugar, brown sugar and pumpkin pie spice.
Add the melted butter and stir until mixture comes together and crumbs form.
Divide streusel topping among the wet batter until evenly distributed.
Bake for 5 minutes, then reduce temperature to 350 degrees.
Bake for 15-17 more minutes.
Let muffins cool in pan for about 10 minutes than transfer to a wire rack to cool.
Whisk together powdered sugar, maple syrup and milk. until smooth.
Drizzle on top of muffins.