Heat the milk in a small saucepan set over medium-low heat.

When the milk begins to steam and bubble around the edges, remove it from the heat– we don’t want it to boil. 

In a large bowl, whisk together the granulated sugar, cornstarch, and egg yolks until they are a pale yellow– about 1 minute. 

Slowly add the hot milk to the egg mixture, whisking constantly. If there are any large lumps in your mixture, pour it through a fine mesh sieve before returning it to the saucepan. 

Cook the egg-milk mixture over medium-low heat for 4-5 minutes, or just until it begins to boil and thicken. Whisk often so the mixture doesn’t scorch. 

When the cream is thick enough to coat the back of a spoon, remove it from the heat and whisk in the vanilla. 

Transfer the pastry cream to a clean bowl and cover the surface with plastic wrap– make sure the plastic is touching the surface of the cream or it will form a skin. 

Place the pastry cream in the fridge and chill completely– about 2 hours. 

Add the chopped chocolate to a medium bowl. 

Heat the heavy cream in a small saucepan set over medium-low heat, just until it begins to steam. 

Pour the heavy cream over the chocolate and allow it to sit for 1 minute. 

Whisk the chocolate and cream together until the ganache is smooth. Set the ganache aside to cool for 2 hours. In the meantime, prepare the crusts (below). 

Preheat the oven to 400F and grease four small (4”-5”) tart pans with nonstick baking spray. 

Cut two circles (about 6” in diameter) from each pie crust and press one into each prepared tart pan. Make sure not to stretch the pie crust or it will shrink when baked. Poke the bottom of each tart shell a few times with a fork. 

Bake the tart shells for 15-17 minutes, or until they are crisp and golden brown. You can fill the tart shells with pie weights, but it is not necessary.

Allow the tart shells to cool completely before removing them from the pans. 

Place 2-3 tablespoons of ganache into the bottom of each tart shell and spread it to the edges. 

Top the ganache with the cooled pastry cream, filling the shells completely. 

Add the remaining ganache to a small bowl and beat it on medium speed with a hand mixer until light and fluffy– about 4-5 minutes. 

Transfer the whipped ganache to a piping bag and pipe it on top of the pastry cream.
Garnish with chocolate sprinkles or shavings, if desired. 

Serve the tarts immediately or store them at room temperature for up to four hours. I do not recommend storing these tarts assembled overnight as the crust will become soggy.