Begin by creaming together the butter and sugar until smooth and creamy, about 2 minutes. Gradually add in the vanilla extract, followed by the flour and salt, mixing until just combined.

Wrap the dough tightly in plastic wrap, forming it into a disc shape, and chill in the refrigerator for at least 30 minutes.

Preheat the oven to 350°F (175°C). Ensure your oven is fully preheated before baking.

Roll out the chilled dough to about ⅛ inch thick. Cut out circles to fit into a muffin tin and press the dough into the tin. Fill each shell with strained raspberry jam and bake for 18-20 minutes or until lightly golden.

After baking, let the tarts cool in the tin for about 5 minutes before transferring them to a wire rack to cool completely.