In a large bowl, cream the butter and sugar together until light and smooth.

Add the egg and vanilla extract. Mix well using spatula until fully combined.

Gradually add the flour in two additions, mixing after each. Once the dough starts to come together, knead it gently into a smooth ball.

Flatten the dough slightly into a disc shape, wrap it tightly in plastic wrap, and refrigerate for at least 2 hours to chill and firm up.

Once chilled, roll out the dough on a lightly floured surface to about 1/4-inch thickness.

Use a round sableé cutter to cut out the cookies. For half of the cookies, use a small decorating tip or mini cutter to create a circle in the center.

Place the cookies on a baking sheet lined with parchment paper.

Bake in a preheated oven at 170°C (340°F) for 13–15 minutes, or until the edges are lightly golden.

Remove the cookies from the oven and immediately sprinkle confectioners' sugar over the top cookies (the ones with the center cut out) while still warm.

Allow the cookies to cool completely.

Once cooled, spread about half a teaspoon of strawberry jam onto the whole cookies. Gently sandwich with the sugar-dusted cookies on top.