01 -
Preheat oven to 300°F (150°C). Grease and flour a 10-inch tube pan and line the bottom with parchment paper.
02 -
Cream together the sugar, butter, and shortening in a large bowl using an electric mixer until light and fluffy.
03 -
Sift together the cake flour, baking powder, and salt in a separate bowl.
04 -
Alternate additions: Add the flour mixture, eggs, and heavy cream to the butter mixture, beginning and ending with the flour. Mix on low speed until just combined.
05 -
Stir in the Key lime juice, lime zest, and vanilla extract. Do not overmix.
06 -
Pour the batter into the prepared pan and spread evenly. Bake for about 1 hour 30 minutes, or until a toothpick inserted in the center comes out clean.
07 -
Cool in the pan for 15 minutes before transferring to a wire rack to cool completely.
08 -
Whisk together powdered sugar, Key lime juice, and vanilla extract until smooth.
09 -
Drizzle or brush the glaze over the cooled cake. Let it set before slicing.