I love the taste of key limes, but I'm not a big fan of key lime pie. Wanting a dessert that gave the same punch of flavor, I created this cake recipe. By adding the key lime syrup at the end while the cake is still warm, you're preserving the freshness of the juice. Around our offices, I know a recipe is a success based on how fast it disappears. This one was gone almost before I could get back to the test kitchen.
Preheat the oven to 350 degrees.
Cream the butter and sugar in an electric mixer until soft and light. Add the eggs and continue mixing until smooth. In a separate bowl, whisk together the flour, salt and baking powder. Add in thirds, alternately with the sour cream. Remove the bowl from the mixer and fold in the grated key lime rind. Scrape the cake batter into the prepared cake pan and sprinkle the pepitas evenly over the top. Place the cake on the middle rack and bake for 45 to 50 minutes or until the cake is golden brown and a skewer inserted in the middle comes out clean.
While the cake is baking, whisk together the key lime juice and superfine sugar in a small bowl. Continue mixing until all the sugar is dissolved. Set aside.
Cool the cake in the pan on a wire rack for 15 minutes. Then, using a wooden skewer, poke holes all over the surface of the cake. Spoon the key lime syrup evenly over the cake while it's still warm. You can unmold the cake once it's completely cooled.