Place the softened butter in a large bowl and mix with a silicone spatula until smooth and creamy. Add the powdered sugar and continue mixing until fully incorporated and slightly fluffy.

Add the beaten egg in 2–3 additions, mixing well after each addition until the mixture is fully emulsified before adding more.

Sift in the low-gluten flour and almond flour, then add the salt. Gently mix by hand until no dry flour remains and a smooth, non-sticky dough forms. Do not overwork the dough.

Place the dough between two sheets of parchment paper and roll it out evenly to about 0.5 cm thick. Transfer the dough (with the parchment) onto a baking tray and freeze for 30 minutes, until firm.

Once chilled, use a round cookie cutter to cut out cookies. For half of them, use a smaller cutter to remove the center, creating the cut-out tops. Leave the remaining cookies whole.

Arrange all cookies on a parchment-lined baking tray, leaving about 2 cm of space between each.

Preheat the oven to 150°C (300°F), top and bottom heat. Bake the cookies on the middle rack for 20 minutes, until the edges are lightly golden.

Remove from the oven and let the cookies cool completely on a wire rack. Once cooled, dust the cut-out cookies lightly with powdered sugar if desired.

Melt the white chocolate gently over a double boiler, keeping the water temperature below 60°C (140°F), and stir until smooth.

Pipe or spread a thin ring of white chocolate around the edge of a whole cookie. Place a cut-out cookie on top, align carefully, and gently press to secure. Let sit for about 5 minutes until the chocolate sets.

Once set, fill the center cut-out with strawberry jam. Repeat with the remaining cookies.