In a medium bowl, whisk together the flour, confectioners’ sugar, and salt. Add the cold butter and cut it in using a pastry cutter. Continue until the entire mixture resembles pea-sized crumbs.
Pour in the heavy cream mixture and stir to combine. You can use your hands to really get it all combined, if needed.
Place the dough on a lightly floured surface and flatten it into a 1-inch thick disc. Wrap the dough in plastic wrap and refrigerate for 1 hour or up to 2 days.
Grease a 9-inch tart pan with removable bottom.
Remove the tart dough from the refrigerator and place it on a lightly floured surface. Roll out the pastry crust into a circle slightly larger than your 9-inch tart pan.
Place the pastry into the greased 9-inch tart pan. Carefully transfer the dough to the tart pan by rolling it onto the rolling pin, then gently ease the dough into the pan, pressing it down into the corners and fluted sides of the pan, evenly.
Run the rolling pin over the top of the tart pan so that the excess dough gets cut off, making a clean edge. With the excess dough, you can patch up any areas that may be too thin.
Refrigerate for at least 10 minutes (you can do this while your oven preheats).
Preheat the oven to 400°F (204°C). Remove the tart crust from the refrigerator. Line the inside of the tart with foil and fill it with pie weights (you can use dried beans instead). It is important that you use pie weights to prevent the crust from shrinking or puffing). Alternatively, you can freeze the dough and bake it from frozen without the use of pie weights. From frozen, the tart shell will take about 20 minutes to bake.
Place the tart crust in the oven and bake for 10 minutes. Remove the crust from the oven and reduce the heat to 350°F (177°C). Carefully, remove the foil and weights. With a fork prick a few holes into the bottom of the crust and bake for 5-6 more minutes or until lightly golden brown. Remove from the oven and allow to cool completely before filling it with the pastry cream.