Preheat the oven to 350°
For the streusel:
Melt one stick (8 Tbsp) of butter. Combine the ¼ cup granulated sugar, brown sugar, cardamom, and nutmeg in a bowl. Stir in the melted butter and then 1 ¼ cup flour. Mix well and set aside.
For the cake:
Prepare a 9-inch cake pan by greasing it with 2 Tbsp of butter and dusting with 2 Tbsp of flour. In a large bowl, cream the rest of the butter (6 Tbsp) and sugar (¾ cup) on high speed for 4 to 5 minutes, until light and fluffy. This step adds air to the finished product and should not be skipped. Reduce to low speed and add the eggs 1 at a time. Then add the vanilla, orange zest, and yogurt. In a separate bowl, gently whisk together the rest of the flour (1 1/3 cup), baking powder, baking soda, and salt. With the mixer on low speed, add the flour mixture to the batter until just combined. Fold in the blueberries until just incorporated.
Pour the batter into the prepared pan and even it out. Crumble the topping evenly over the batter. Bake for 40 to 50 minutes, until a toothpick comes out clean. Cool and dust with powdered sugar.