In a medium bowl, whisk together the flour, sugar, and salt.

Cut in the cold butter until the mixture resembles coarse breadcrumbs.

In a separate small bowl, whisk the egg yolks, vanilla, and 1 1/2 tablespoons of milk. Stir this into the dry ingredients.

Form into a disc and wrap with plastic wrap.

Chill for 1 hour. You can also freeze it for up to 3 months. While it’s chilling, you can make the filling (below).

Grease eighteen 2.6” (6.5 cm) fluted non-stick mini tart pans.

Roll out the dough between 2 pieces of parchment paper to about 1/8 inch (3 mm). I used the bottom of a glass (a cookie cutter would give you better, cleaner-cut edges) to make circles that were about 1/4” (6 mm) wider than the widest part of the tart pans, and I still had to trim some away. Do a test to make sure your circles are the right size for your pans. If the dough becomes hard to work with, stick it in the freezer for a few minutes. Then you’ll be able to very easily remove the circle cut-outs. If the circles don’t come off the parchment paper perfectly, it doesn’t really matter since you’ll be pressing them down into the pans and will likely have to trim some off anyway.

Place a circle cut-out over the top of the greased mini tart pan and press it firmly into place. Be sure to press down around the bottom edge to remove any air pockets.

Prick holes over the bottom (not going all the way through the crust, but almost) with a fork. Repeat with the remaining tartlet pans.

Place in the freezer for 20-30 minutes.

Towards the end of the chill time, preheat the oven to 375 °F (190 °C) and place a baking sheet large enough to fit the tartlet pans in the lower third of your oven.

Place the tartlets directly onto the hot baking sheet and bake for 14-17 minutes, rotating the pan halfway through if you notice them browning too quickly in certain areas, until the sides are nicely browned and the bottom has browned.

Remove the baking sheet and tartlets from the oven and place them on a wire rack to cool for about 15-20 minutes before removing the crusts from the pans. To do that, just turn the pan over and let the crust fall into your hand. It’s important to do this while they’re still a bit warm. They came out super easily.

If making ahead of time, you can put the cooled crusts in an airtight container and store them at room temp for up to 3 days.

Place the chocolate and butter cubes in a medium heat-proof bowl.

Heat the cream in a small saucepan over medium heat until hot and steamy.

Pour the cream over the chocolate and butter, cover with plastic wrap or a plate, and let sit for 5 minutes.

Add the vanilla and salt, and stir until the chocolate is totally melted.

Let sit for about 10-20 minutes or until firm enough to easily spoon into the cooled tartlet crusts.

Spoon 1 1/2 tablespoons (22.5 grams) of ganache into each cooled tartlet crust.

If the ganache is still quite runny, let it firm up a bit (a few minutes in the fridge should do) before adding your toppings, if using.

Store assembled tartlets in an airtight container in the refrigerator for up to 3 days. Bring them to room temperature before serving to allow the ganache to soften slightly.