Heat a conventional oven to 350°F / 180°C and line two trays. Rub lemon zest into the 75 g sugar. Beat in butter and vanilla until lighter, then mix in the yolks. Combine flour, baking powder, xanthan and salt and mix into the wet ingredients to make a scoopable dough.

In a wide bowl, alternate three layers of dough with three portions of the 70 g jam. Swirl each jam layer lightly. Fold the finished dough only two or three times, keeping visible jam ribbons.

Stir cream cheese and 25 g sugar smooth. Add warm cream and vanilla to make a loose but spoonable filling. If block cream cheese makes it too firm, add 1–2 tsp more cream.

Scoop 2-tbsp portions into the coating sugar, roll into balls and arrange at least 2 inches apart. Press a well with a 1-tbsp measuring spoon. Use about 2–3 tsp filling in each. Make 14 cookies.

Bake one tray at a time for 12–14 minutes, until the dough has puffed and the filling is set. Keep the waiting tray at room temperature. Cool the cookies completely on their baking trays before moving.

Simmer the strawberries, 40 g jam and cornstarch slurry over medium heat for 3–4 minutes, stirring, until the fruit softens and the juices thicken. Cool fully. Spoon sauce onto cookies just before serving.