Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9-inch round cake pan.
In a medium bowl, stir together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla. Beat in the dragon fruit until smooth.
Stir the flour mixture into the creamed mixture alternately with the sour cream and lime zest. Pour batter into the prepared pan.
Bake for 35 to 40 minutes in the preheated oven, or until a toothpick inserted into the center of the cake comes out clean.
Allow cake to cool in the pan for 10 minutes, then turn out onto a wire rack and cool completely.
Interesting Facts
Dragon fruit is a tropical fruit native to Central and South America.
Dragon fruit is high in fiber and low in calories.
The bright pink flesh of the dragon fruit has a sweet and slightly tart flavor.
Dragon fruit cake is a unique and delicious way to enjoy this exotic fruit.