2 cups butter, plus 1 tsp. to grease pan
2 1⁄2 cups cake flour, plus 1 tbsp. for dusting cake pan
2 1⁄2 tsp. baking powder
1 tsp. salt
1 cup root beer
5 tsp. root beer extract (preferably Zatarain's)
1 1⁄2 cups sugar
4 room-temperature eggs
4 1⁄2 cups confectioners' sugar
2 tbsp. cream
1. Heat oven to 350°. Grease a 9" × 13" pan with 1 tsp. of the butter; dust with 1 tbsp. of the cake flour; tap bottom of pan to remove excess flour.
2. Sift remaining cake flour, baking powder, and salt into a bowl; set aside.
3. Whisk together root beer and 2 tsp. of the root beer extract in a bowl; set aside.
4. Beat sugar and 1 cup of the butter in a large bowl until fluffy. Add eggs one at a time, beating briefly after each addition. Alternately add flour mixture and root beer mixture, waiting for each to be incorporated before adding the next. Mix briefly, then transfer batter to pan; smooth out top.
5. Bake, rotating once, until a toothpick inserted in the middle comes out clean, about 30 minutes. Let cool.
6. Put confectioners' sugar and remaining butter into a bowl; beat with an electric mixer to combine. Add cream and remaining root beer extract; beat to make a fluffy frosting. Spread frosting on cake, making swirls and whorls. Decorate with root beer candies.
SERVES 6 – 8