Prepare the Tart Shell: In a food processor, pulse the flour and powdered sugar. Add the cold butter and pulse until the mixture resembles coarse crumbs. Add the egg yolk and ice water, pulsing just until the dough comes together. Do not overmix.
Form the dough into a disk, wrap it, and chill for at least 30 minutes.
On a lightly floured surface, roll the dough out to an 11-inch circle. Carefully transfer it to a 9-inch tart pan with a removable bottom. Press the dough into the bottom and up the sides. Trim the excess dough.
Freeze the shell for 15 minutes. Preheat your oven to 375°F (190°C).
Line the chilled shell with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes. Remove the weights and paper, then bake for another 8-10 minutes until lightly golden. Let the crust cool completely on a wire rack.
Make the Ganache: Place the chopped chocolate in a heatproof bowl. Heat the heavy cream in a small saucepan until it just simmers around the edges. Do not boil.
Pour the hot cream over the chocolate. Let it sit undisturbed for 5 minutes.
Add the room temperature butter and vanilla extract. Whisk slowly from the center outward until the mixture is completely smooth and glossy.
Assemble the Tart: Pour the warm ganache into the cooled tart shell. Gently tap the pan on the counter to release any air bubbles.
Arrange the halved strawberries on top of the ganache. You can press them slightly into the surface or arrange them decoratively.
Chill the tart for at least 4 hours, or until the ganache is firm. Remove the tart ring before slicing.
Notes
For a richer flavor, you can substitute 1 tablespoon of the heavy cream with a dark rum or brandy before heating.
Use chocolate with at least 60% cacao content for a firm, intensely flavored ganache.
If the ganache seems too soft after chilling, place it in the freezer for 15-minute intervals until set.