Start by making the tart dough. In a food processor, add the flour, powder sugar, and salt, and mix until combined.
Add cold cubed butter, and blend until there are pea-sized pieces of butter. If you dont have a food processor, you can do it by hand, mixing the cold butter into the flour mixture. Make sure that your hands are cold.
Then, add the egg, and the vanilla extract and mix until a dough forms. Try not to overmix the dough.
Cover the dough with plastic wrap and let it chill in the fridge for at least an hour.
Transfer the dough onto a clean floured surface and roll with a rolling pin into a circle and transfer it into a 9-inch tart pan. Cut off the extra edges. Make little holes with a fork and freeze for 20 minutes.
Bake in a 180c (350f) preheated oven for about 15-20 minutes or until the crust is a light golden brown color. Remove from the oven and let it cool while making the filling.
Make the lemon curd:
Put all of the ingredients in a saucepan and cook it over medium-low heat whisking constantly.
Once the butter melt, the consistency of the mixture will be thin, dont increase the heat. Keep whisking until the mixture thickens for about 5 minutes.
When the mixture thickens, transfer it to a fine-mesh strainer set over and bowl and strain the mixture from any unnecessary lumps. This will give you a perfect and smooth curd.
Cover the bowl tightly with plastic wrap and let the mixture cool for about 20-30 minutes.
Pour the curd into the tart crust and smooth it out with a spatula. Bake the tart in a 180c (350f) preheated oven for about 10 minutes or until the edges are set.
Refrigerate the tart for at least 2 hours, cut, and serve!
Notes
Dont let the lemon curd come to a boil! This will cook the eggs and leave you with scrambled eggs. Make sure that the lemon curd mixture cooks over medium-low heat.
Use COLD butterfor the crust, we suggest cutting the butter into cubes and then placing it in the fridge, so when you are ready to use it, it will be very cold.
If the crust puffs a bit while baking, press it down using a cup.
Constantly whisk while making the curd! It is really important if you want to get a smooth and silky curd.
Use room temperature ingredients. It is important that you use room-temperature ingredients like butter. This step ensures that your mixture mixes into a homogenous mixture.
Use an easy-release tart pan. We use an easy-release tart pan for all of our tart recipes. This makes sure that your tart will be easy to release from the pan.
Before you start to make this recipe, measure and prepare your ingredients so the cooking process will go smoothly and easily.