Preheat oven to 350°F (175°C) and grease your cake pan.
In one bowl, whisk together flour, baking powder, baking soda, cinnamon, nutmeg, and salt.
In another bowl, beat sugar and butter until fluffy.
Add eggs, pumpkin, and vanilla to the butter mixture. Mix until smooth.
Gradually add dry ingredients to wet ingredients, mixing until just combined.
In a small bowl, combine streusel topping ingredients and mix until crumbly.
Pour half the batter into the pan and top with half the streusel.
Add the remaining batter and sprinkle the rest of the streusel.
Bake for 40-45 minutes or until a toothpick comes out clean.
Let the cake cool for 10 minutes, then transfer to a cooling rack.