Ingredients

For the Blueberry Cake
• 1½ cups (170 g) all-purpose flour
• 1½ cups (170 g) cake flour
• 2 teaspoons baking powder
• ¾ teaspoon kosher salt
• ¾ teaspoon ground ginger
• ¼ teaspoon baking soda
• 1 cup plus 2 tablespoons (225 g) granulated sugar
• ¼ cup plus 2 tablespoons (90 ml) canola oil
• 2 ounces (½ stick/55 g) unsalted butter, softened
• 1 large egg
• 1 large egg yolk
• 2 teaspoons pure vanilla extract
• Zest of 1 lemon (about 1 tablespoon)
• ¼ cup (60 ml) heavy cream
• ½ cup (115 g) sour cream
• 4 cups (14 ounces/395 g) fresh blueberries
For the Streusel
• ¾ cup (165 g) firmly packed dark brown sugar
• 1?3 cup (40 g) all purpose flour
• 1?3 cup (40 g) cake flour
• ¾ teaspoon ground cinnamon
• 3 ounces (¾ stick/85 g) unsalted butter, melted and cooled slightly

Instructions

Make the cake
1. Preheat the oven to 375°F and prepare a 10-cup tube pan or a 10 inch round springform cake pan by lining with parchment and spraying with nonstick cooking spray. (Or butter the pan and dust it with flour, knocking out the excess flour)).
2. In a large bowl, whisk together both flours, the baking powder, salt, ginger, and baking soda. Set aside.
3. In a small bowl, whisk together the cream and sour cream and whisk until combined; set aside.
4. In the bowl of a standing mixer fitted with the paddle attachment, beat the butter, oil and sugar on medium speed until light and fluffy, about 3 to 4 minutes.
5. Add the egg and egg yolk and beat until incorporated. Scrape down the sides and bottom of the bowl,
6. Add the vanilla extract and lemon zest, and beat for another 10 seconds
7. Add the flour mixture to the butter mixture in the standing mixer in three parts, alternating with the cream mixture, beginning and ending with the flour mixture (flour-cream-flour-cream-flour). Beat at medium speed after each addition until incorporated, about 10 to 15 seconds each.
8. Using a rubber spatula, gently fold the blueberries into the batter. The batter will be very thick.
9. Transfer the batter to the prepared pan, smoothing the top with a spatula.
Make the Streusel
10. In a medium bowl, whisk together the brown sugar, flours, and cinnamon until combined (lumps are okay).
11. Drizzle the melted butter over the mixture and combine until the sugar mixture is thoroughly moistened. You can do this with your hands, a fork, or a spatula.
12. Pinch off chunks of the topping and drop them over the top of the buckle batter. Use all of the topping and cover the batter completely.
13. Bake the cake until a toothpick inserted in the center of the cake comes out with a few moist crumbs, 50 to 60 minutes. (Note: Baking time for muffin size was between 15 to 20 minutes)
14. Set the cake pan on a wire rack to cool for at least 20 minutes. Loosen the cake from the sides of the pan with a paring knife, then push the bottom of the pan up (If using a removable bottom) to release the cake. Use the knife to loosen and remove the cake from the bottom of the pan, then cool completely, topping side up, on a cooling rack.

Notes