Preheat your oven to 350ºF.
Line your cake pan with parchment paper and give it a spritz of oil.
In a mixing bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon.
In another bowl, beat together the butter, oil, and sugar until creamy. Then, mix in the eggs, vanilla, and sour cream.
Gently fold in the flour mixture.
Spread a third of the batter in the pan, then mix the remaining batter with half of the blueberries.
Pour the batter into the pan, top with the rest of the blueberries, and sprinkle on the streusel.
Bake for 55 to 65 minutes, until golden and a toothpick comes out clean.