4 oz/115 g unsalted butter, cubed and softened to room temperature
¼ cup/50 g sugar
1/8 tsp fine sea salt
1 ½ cups/210 g all-purpose flour
1 large egg, lightly whisked
1 tsp vanilla extract
¼ cup demerara sugar
¼ cup seedless jam, chocolate spread, or fruit curd
- Place the butter and sugar in the bowl of a stand mixer and beat over medium-high speed until pale yellow and creamy, 2 to 3 minutes. Scrape down the sides of the bowl. Add the salt and all-purpose flour and beat over low speed until the mixture turns into a coarse crumbly mix. Scrape the sides of the bowl down. Add the egg and vanilla and mix over medium speed until it forms a smooth and pliable dough, about 1 minute. Scrape the sides of the bowl down and transfer the dough to a bowl. You should have about 14 ½ oz/415 g of cookie dough. Cover with a tight lid or cling film and let refrigerate for at least 4 hours, preferably overnight.
- When ready to bake, preheat the oven to 350F/180C. Line two baking sheets with parchment paper. Place the demerara sugar in a small mixing bowl. Take 1 Tbsp of the dough (about 18 g), and using the palms of your hands, shape into a small ball. Toss the ball in the demerara sugar to coat evenly. Place the ball of dough onto the lined baking sheet. Press gently with your thumb to form a small well. The well should not pass through the bottom. Prepare the remaining cookies and space them 1.5 in to 2 in/2.5 cm to 5 cm apart from each other on the sheets. Bake the cookies in the oven for 20 minutes, until they turn golden brown on the edges, rotating the sheets halfway through during cooking. Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely. Transfer to an airtight container and store in the freezer for up to 2 weeks.
- When ready to serve, fill the cookies with jam, chocolate spread, or fruit curd. If the cookies are frozen, thaw them to room temperature before filling them, and using two teaspoons, spoon in just enough filling, about 1 tsp, into the well of each cooled cookie. Serve the cookies and eat within a few hours of preparing them.
- It’s best to let the dough rest overnight in the refrigerator for a crispier texture.
- For the cookie filling, use whatever jam you love and a seedless variety for berry-based jams like raspberry and blackberry (many people find the texture of the seeds annoying). Fruit curds like lemon, lime, orange, and passion fruit are excellent options, as well as gianduja and other chocolate spreads.