To begin, line a quarter sheet baking pan (5″ x 9″) with parchment paper and set aside.
Then, prepare the custard. Add the milk and lemon zest to a small saucepan and heat over low heat.
In a separate bowl, whisk the egg yolks and sugar until the mixture is smooth and pale yellow. Sift the flour and cornstarch into the egg mixture. Add a ladleful of warm milk to loosen the mixture and whisk until it is smooth and homogenous.
Then, add the mixture to the remaining warm milk, whisking continuously until the custard thickens, about 3-5 minutes. The custard should be very thick.
Spread the custard evenly into the prepared sheet pan. Allow the custard to cool completely, about 3-4 hours, uncovered at room temperature, or chill it in the refrigerator.
Once the custard is set, lift the it from the baking pan, turn the slab out onto a smooth work surface, carefully peeling away the parchment paper. To cut the custard into the characteristic diamond shape, slice the custard in horizontal lines spaced 1 1/2″ apart, then cut a series of parallel diagonal lines across the entire slab at a 60° angle. For smoother cuts, use a knife dipped in warm water, wiping the blade clean between each cut. In a heavy bottomed fry pan or deep fryer, add oil to a depth of at least 2″, and heat to 350°F. Set up a breading station using three shallow bowls. Add the flour to one bowl, lightly beat the eggs in the second bowl, and add the breadcrubs to the third bowl. Dredge each diamond in flour, then dip in the egg mixture and then coat in breadcrumbs. Repeat this process until all of the custard is breaded. Working in batches, fry the custard until golden brown, about 3 minutes. Remove the custard with a slotted spoon and allow them to drain on a cooling rack or on paper towels while you fry the rest.
Then, arrange them on a platter and dust with powdered sugar or, for a dramatic presentation, sprinkle room temperature brandy or rum over the top and light them on fire, turn down the lights and watch them come to life! See tips below for how to flambé safely.
How to flambe safely:Use an 80 proof liquor or 40% alcohol by volume (rum or brandy suggested). Beer, champagne and wine will not work because the alcohol content is not high enough, while liquors above 120 proof would be dangerous.Heat the brandy or rum in a saucepan or microwave in a microwave safe container before igniting. Do not bring it to a boil or you will burn the alcohol off, but heat it until you can see bubbles around the edges.Arrange the crema fritta in a flambé pan, or skillet with a long handle. Splash about 1/4 cup of liquor over the top and using a long match, ignite the fumes at the edge of the pan (not the liquid itself).Precautions: be careful not to lean over the dish as you light it on fire, never pour liquor from a bottle into a pan that is near an open flame because the flame can follow the stream of alcohol into the bottle and cause it to explode and keep a pot lid or fire extinguisher within reach, just in case you need it!
