2 cups butter, softened
2-1/2 cups sugar
6 large eggs, room temperature
2 teaspoons grated key lime zest
2 tablespoons Key lime juice
1 tablespoon vanilla extract
4 cups all-purpose flour
3/4 cup 2% milk
1 package (8 ounces) cream cheese, softened
1/2 cup butter, softened
1 teaspoon grated key lime zest
1 tablespoon Key lime juice
3-3/4 cups confectioners’ sugar
Preheat oven to 350°. Grease and flour a 10-in. fluted tube pan. In a large bowl, cream butter and sugar until light and fluffy. Add 1 egg at a time, beating well after each addition. Beat in lime zest, vanilla and lime juice. Add flour alternately with milk, beating well after each addition. Transfer to prepared pan.
Bake until a toothpick inserted in center comes out clean, 1-1/4 to 1-1/2 hours. Cool in pan 10 minutes before removing to a wire rack to cool completely. For frosting, in a large bowl, beat cream cheese, butter, lime zest and lime juice until smooth. Gradually beat in confectioners’ sugar. Spread over cake. If desired, garnish with lime slices and additional zest.