Step 1

Crumble: Mix flour, sugar, butter, and miso in a small bowl until combined. Let sit until ready to use.

Step 2

Cake: Preheat oven to 350°. Lightly grease a 9" cake pan with butter. Lightly dust with flour, tapping out excess. Whisk baking powder, salt, baking soda, and 1¾ cups flour in a large bowl to combine.

Step 3

Whisk eggs, brown sugar, and yogurt in a medium bowl. Add vanilla and 1 cup melted butter and whisk to combine. Using a rubber spatula, mix dry ingredients into egg mixture until well combined, but do not overmix. Mix in blueberries.

Step 4

Transfer batter to prepared pan and spread in an even layer. Top with reserved crumble.

Step 5

Bake cake, checking after 30 minutes and tenting with foil only if crumble is getting very dark (some color is fine), until top of cake is firm and a tester inserted into the center comes out clean, 60–70 minutes total. Let cake cool in pan, at least 2 hours, then cut into slices in pan.

Step 6

Do Ahead: Cake can be made 1 day ahead. Tightly wrap and store at room temperature.