Preheat oven to 350°. Spray a 9-inch enamel-coated cast-iron skillet with baking spray with flour.
In a large bowl, whisk together flour, sugar, cocoa, 2 tablespoons espresso powder, baking powder, and salt; whisk in buttermilk, melted butter, eggs, and vanilla until combined. Spread batter into prepared pan.
Bake until a wooden pick inserted in center comes out clean, 30 to 35 minutes. Let cool completely.
In a medium bowl, beat cream, confectioners’ sugar, and remaining 1 tablespoon espresso powder with a mixer at medium-high speed until stiff peaks form. Spread onto cooled cake. Garnish with chocolate-covered espresso beans, if desired. Serve immediately.
Recipe by Paula Deen Magazine at https://www.pauladeenmagazine.com/mocha-chocolate-cake/