Preheat your oven to 350°F (175°C) and grease your Bundt pan.
In one bowl, whisk together flour, baking powder, baking soda, and salt.
In another bowl, cream sugar and butter until light and fluffy.
Add eggs, vanilla, and sour cream to the butter mixture and mix until combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
In a small bowl, combine streusel topping ingredients and mix until crumbly.
Pour half of the batter into the Bundt pan and sprinkle half of the streusel topping.
Add the remaining batter and top with 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 remove from the pan and transfer to a cooling rack.