For the key lime curd: In the bowl of a double boiler, mix together the yolks, lime juice, sugar and butter. Cook until a candy thermometer reads 183 degrees F. Cool the bowl in an ice bath and then transfer the curd to a squeeze bottle or pastry bag.
For the dough: In a stand mixer fitted with a paddle attachment, mix the cream cheese until smooth. Add the sugar and blend. In a medium bowl mix the flour, baking powder and salt. In a separate bowl mix the vanilla extract and the eggs. With the mixer running, alternately add the dry and wet ingredients and mix until smooth.
In a frying pan pour enough oil to cover the doughnut bites. Heat the oil over medium heat until a deep-frying thermometer inserted in the oil reaches 350 degrees F.
Scoop 1 ounce of the doughnut batter into the hot oil and fry until golden brown. Repeat for the remaining dough batter. Scoop out the doughnut balls with a slotted spoon, then toss in some sugar and fill the centers with some key lime curd.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Yardbird Southern Table and Bar, Miami, Florida