Strawberry Rhubarb Upside-Down Cake - Chew Nibble Nosh

Ingredients

• For the caramel:
• 1 tablespoon unsalted butter, plus a little extra to butter the pan with
• 1/2 cup sugar
• 1 1/2 cups fresh rhubarb, peeled, halved lengthwise and cut into 1/2-inch pieces
• 1 1/2 cups strawberries, hulled and thinly sliced
• 1 tablespoon cornstarch
• 2 tablespoons strawberry jam
• Dash of kosher salt
• For the cake:
• 1 3/4 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 3/4 cup milk
• 1/4 cup sour cream
• 1 stick unsalted butter, softened, at room temperature
• 1 cup sugar
• 2 large eggs
• 1 teaspoon pure vanilla extract