Plum Cake

Ingredients

• 3/4 cup (1 1/2 sticks) unsalted butter, room temperature, plus more for pan
• 1 1/2 cups plus 2 Tablespoons all-purpose flour (spooned and leveled)
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup packed light brown sugar
• 1/2 cup granulated sugar
• 3 large eggs
• 1 teaspoon pure vanilla extract
• 2 teaspoons finely grated lemon zest
• 1/4 cup sour cream
• 3 plums, halved, pitted, and cut into eighths
• for dusting confectioners sugar