Fluted round cookie cutter and small heart-shaped cutter
Kitchen scale optional, but recommended
Method
In a large mixing bowl, beat the softened butter and sugar together for 1–2 minutes, until smooth and creamy. Add the egg and vanilla extract, mixing until combined.
In a separate bowl, whisk together the flour, cornstarch, and salt. Add to the butter mixture, followed by 15 ml (1 tbsp) of milk. Mix on low speed until a soft dough forms, adding up to another 5 ml (1 tsp) of milk if needed. Gently bring the dough together with your hands until smooth and pliable.
Flatten the dough into a disc, cover, and refrigerate for approximately 10 minutes, until slightly firm but still easy to roll.
Roll the dough to approximately ⅛ inch (3–3.5 mm) thick between two sheets of parchment paper. Using a fluted round cookie cutter, cut an even number of biscuits. Cut a small heart-shaped opening from the center of half the rounds. Arrange on parchment-lined baking sheets and refrigerate for 10–15 minutes.
Preheat the oven to 350°F (175°C) conventional. Bake one tray at a time on the center rack for approximately 10 minutes, until the biscuits are set and only lightly golden around the edges. They should remain mostly pale.
Allow the biscuits to rest on their baking sheets for 5 minutes before carefully transferring them to a wire rack to cool completely.
Gently simmer the raspberry preserves in a small saucepan over medium-low heat for 2–3 minutes, stirring frequently, until slightly thickened. Allow to cool completely.
Turn the whole biscuits upside down, placing approximately 1 tsp raspberry filling onto each. Top with the heart-cut biscuits and gently press together until the raspberry filling is visible through the centers.
Notes
Dough consistency: The dough should be soft and cohesive without being sticky. If it becomes too soft while rolling, refrigerate briefly. If it feels too firm and cracks, allow it to soften slightly before continuing.Sugar: I recommend superfine (caster) sugar for the best biscuit texture, but regular granulated sugar will also work.Raspberry preserves: I used Bonne Maman Raspberry Preserves, keeping the seeds for a more homemade finish. Seedless raspberry jam also works. Reduce the filling only until slightly thickened, as it will continue to firm up as it cools.Cookie cutters: A dedicated Jammy Dodger cutter creates the fluted rounds and heart-shaped centers, but an ordinary fluted round cutter and a small heart-shaped cutter work equally well.Make ahead: These biscuits are particularly delicious after 1–2 days in an airtight container. The biscuits become slightly softer and the raspberry filling develops a stickier, chewier consistency.Storage: Store in an airtight container at cool room temperature for approximately 3–4 days.