Melted unsalted butter, for buttering the pan
3/4 cup granulated sugar
1/2 cup old-fashioned rolled oats
1 teaspoon baking powder
1/2 teaspoon kosher salt
1/4 teaspoon baking soda
1 1/2 cups plus 1 tablespoon all-purpose flour (see Cook's Note)
1/2 cup vegetable oil
1/2 cup plain yogurt
1 teaspoon pure vanilla extract
2 large eggs
1 1/4 cups blueberries, plus more for topping
1/2 cup plain yogurt
One 8-ounce package cream cheese, at room temperature
1 teaspoon pure vanilla extract
1/2 cup confectioners' sugar
1/4 cup blueberry preserves, for topping
When measuring flour, we spoon it into a dry measuring cup and level off excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.)