Ingredients
Cake:
- 1 cup butter, at room temperature
- ½ cup shortening
- 3 cups sugar
- 6 eggs, at room temperature
- 3 cups flour
- ½ teaspoon baking powder
- ⅛ teaspoon salt
- 1 cup milk
- 1 teaspoon vanilla extract
- 1 teaspoon lime zest
- ¼ cup fresh Key lime juice
Frosting:
- 1 ½ cups powdered sugar, sifted
- 1 ½ tablespoons fresh Key lime juice
- 1 ½ tablespoons water
- 2 teaspoons melted butter
- ½ teaspoon vanilla extract
Instructions
- Preheat oven to 325°.
- Beat butter and shortening at medium speed with a heavy-duty electric stand mixer until creamy.
- Gradually add sugar, beating at medium speed until light and fluffy.
- Add eggs, 1 at a time, beating just until blended after each addition.
- Whisk together flour, baking powder, and salt. Add to butter mixture alternately with milk, beginning and ending with flour mixture. Beat at low speed just until blended after each addition.
- Stir in vanilla, lime zest, and lime juice.
- Pour batter into a greased and floured 10-inch solid tube pan.
- Bake at 325° for 1 hour and 15 minutes to 1 hour and 20 minutes or until a toothpick inserted in the center comes out clean. Cool in pan on a wire rack for 15 minutes, then invert onto a wire rack.
- Whisk together powdered sugar, Key lime juice, water, melted butter, and vanilla until smooth.
- Scrape the frosting into a quart Ziploc bag, seal, and snip the tip off one corner. Drizzle back and forth over the top of the cake.