Upside Down Praline Skillet Cake

Topping

toasted pecans, chopped

⁄2 cup unsalted butter, diced

⁄2 cup firmly packed light brown sugar

⁄4 cup light corn syrup

fresh lemon juice

⁄4 teaspoon salt

Cake

⁄2 cup unsalted butter, softened

firmly packed light brown sugar

large eggs

⁄2 cups self-rising flour

⁄2 cup whole buttermilk

⁄2 teaspoon vanilla extract