Citrus Upside-Down Cake Gelson's

Ingredients

• 2 sticks plus 3 Tbsp unsalted butter, at room temperature
• ⅔ cup light brown sugar
• 2 tsp fresh lemon juice
• 2 small grapefruit (adjust for other citrus)
• 1 cup fine cornmeal
• ½ cup all-purpose flour
• 1 ½ tsp baking powder
• ½ tsp fine sea salt
• 1 cup granulated sugar
• 4 large eggs, at room temperature
• ⅓ cup sour cream
• 2 tsp vanilla extract