To make the streusel: In a medium bowl, toss together flour, vanilla sugar, cinnamon, baking powder and salt. Gradually stir in 1 tablespoon oil at a time until the mixture looks crumbly.
To make the cake: In a medium bowl, whisk together flours and baking powder.
In another medium bowl, whisk together maple syrup, oil, vanilla and salt. Pour into the dry ingredients and stir just until combined. Gently fold in the blueberries.
Scoop the mixture into a 9" springform pan lightly coated with nonstick spray. Use an off-set spatula to smooth the top. Scatter the top with the crumbly streusel mixture.
Bake until toothpick placed near the center comes out mostly clean with a few moist crumbs attached, about 60 to 70 minutes. Remove and place on a wire rack - after amount 30 minutes, remove the sides and let completely cool before cutting.