Heat oven to 350℉/177℃.
Spray bundt pan with baking spray. Set aside.
In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and pumpkin pie spice.
Add vegetable oil, milk, eggs, vanilla, and pumpkin purée.
Mix until smooth.
Pour half of batter into prepared pan.
Top with streusel, being careful not to let it touch the sides or center of the pan.
Top with remaining batter.
Bake for 45 minutes, or until cake tests done.