260 g all-purpose flour
1/4 teaspoon salt
225g butter at room temperature
60g icing sugar
1 tsp vanilla extract

Shortbread Cookies: In a bowl mix the flour with the salt.
beat the butter until smooth (about 1 minute). Add the sugar and beat until well combined. Beat in the vanilla extract. Gently stir in the flour mixture just until incorporated.
Divide the dough in half and then roll each half between two sheets of parchment or wax paper until it is about 6mm thick. Place the dough on a baking sheet (along with the parchment paper) and place in the refrigerator until firm (about 30-60 minutes).
Once chilled, remove from fridge and peel off the top piece of baking paper. Using a 7 cm heart shaped cookie cutter, cut out the cookies. Use a smaller heart shaped cookie cutter to cut out the centers of half of the cookies. (You will be sandwiching two cookies together and there will be a small ‘window or cut out’ in the top cookie so you can see the jam underneath.) Place the cookies on a baking sheet lined with baking paper spacing the cookies about 5 cm apart. Then put the baking sheet with the unbaked cookies in the refrigerator to chill while you preheat the oven to 180 degrees.
Bake the cookies for about 10 minutes, or just until cookies are lightly browned around the edges. Cool on a wire rack.
To Assemble Cookies: Place the cookies with the cut-outs on a wire rack and dust tops with the icing sugar.
On the bottom surface of the full cookie spread a thin layer of jam (about 1/2 teaspoon). Place the cut-out cookie on top and gently sandwich them together.