Cake

1.  Heat oven to 350 degrees F. Line a round spring form pan (22 cm) or deep dish pie pan with parchment paper. Press parchment to fit sides of the dish (the cake will weigh it down when you put it in the dish). 
2. In a large mixing bowl, sift together the flour and baking powder. Add the sugar. Stir to combine.
3. Add in the beaten egg and begin to combine with hands until roughly incorporated.
4. Add cold butter and start working together, with hands, to form crumble like texture. Once the cake crumble is an even mixture of pea sized crumbles place in the fridge for 30 minutes. Meanwhile, make Italian Cream. 

Italian Cream (Crema Pasticcera) 

1. In a medium mixing bowl whip the egg yolks and sugar with an electric mixer until light and foamy, about 5 minutes. Add the corn starch and mix again for 1-2  minutes until smooth and combined. 
2.  In a sauce pan heat the milk on low heat. Add lemon zest and vanilla bean. Stir to combine. Now, turn heat to medium and heat milk until a soft boil (little bubbles on the sides and steam starts to form).
3. When the milk is hot, remove from heat. Using a whisk- start adding the beaten egg, sugar, and cornstarch mixture, a little at a time into the milk. It’s very important to stir constantly until you achieve a unified mixture. 
4. Put the saucepan back on low heat and continue whisking. Simmer for about 3-4 minutes until the cream begins to thicken. It’s very important that the cream NEVER BOILS. In this way you have a smooth cream without lumps and without chunks of cooked egg.
5. If you have a cooking thermometer you can check that the temperature never exceeds 85°C (185 F). Otherwise, as soon as you see that bubbles begin to form in the cream, lower the heat. You can even remove it from the heat for a few seconds and put it back. This step is the only difficult step in the Pastry Cream recipe.
6. When the cream is well thickened, immediately pour it into a cold glass container. Important to remove the cream immediately from hot saucepan to prevent it from cooking longer.
7. While cooling, cover the cream with plastic wrap. Keep it in contact with the cream. This step is to avoid forming a skin on the cream surface.

Assemble cake and cream:

1.  Take cake crumble out of the refrigerator. Layer half of the mixture in the prepared cake pan. gently press to form an even layer on the bottom and about 1/2″ inch on the sides of the pan.
2. Add the prepared Italian cream on top of the crumb layer and spread evenly to make a uniform layer.
3. Add the rest of the cake crumb on top of the cream layer. Gently form a uniform layer with hands. Do not press down. Optional: sprinkle with almonds. 
4. Bake 350 degrees F for 30-40 minutes. Let cake cool before cutting and serving. Before serving dust with powdered sugar, Store leftovers in refrigerator.