Grapefruit Olive Oil Cake

Preheat oven to 325°F. Grease and lightly flour a 9x5x3-inch loaf pan; set aside. In a small bowl combine the grapefruit peel and 2 tablespoons sugar; set aside. In another bowl combine the flour, baking powder, baking soda, and salt; set aside. In a large bowl beat the butter and olive oil with an electric mixer on medium speed for 30 seconds. Add 1 cup sugar and beat for 5 minutes, scraping bowl occasionally. Add the eggs, one at a time, beating until just combined after each addition. Combine the buttermilk and 1/4 cup grapefruit juice. Alternately add the buttermilk mixture and flour mixture to the beaten mixture, beating just until combined after each addition.

Spread batter into prepared pan. Bake for 45 to 50 minutes or until a toothpick inserted near the center comes out clean. Cool cake in pan on a wire rack for 30 minutes. Remove cake from pan and poke the top generously with a toothpick or a skewer. In a small bowl combine remaining 2 tablespoons grapefruit juice and 2 teaspoons sugar; brush over top of cake. Sprinkle cake with reserved sugar mixture. Cool completely. If desired, serve with grapefruit slices.