Plum Upside-Down Cake Recipe

Ingredients

• 2 tablespoons butter
• 2 tablespoons brown sugar, or to taste
• 1.5 tablespoons blanched almond flour
• 3 plums, pitted and sliced
• 0.5 cup unsalted butter, softened
• 0.5 cup white sugar
• 1 egg, at room temperature
• 0.75 teaspoon vanilla extract, or to taste
• 1.5 cups all-purpose flour
• 2 teaspoons baking powder
• 0.5 teaspoon salt
• 0.5 teaspoon ground cinnamon
• 1 cup milk, at room temperature