Start by making the Cheesecake filling - combine all ingredients in a small bowl. Dollop 1 tsp sized scoops onto a lined baking tray and freeze.
Make the cookie dough: In a large bowl, using an electric/stand mixer (or hand whisk, just double/triple the times) combine the butter and both sugars on medium speed for several minutes, until fully combined. Add the egg and vanilla and mix again.
Add the flour and baking powder, plus a pinch of salt, and fold in using a rubber spatula or wooden spoon, until just combined. The dough should be fairly solid at this stage (it ought to almost form a ball, albeit a very soft one!). Add the chocolate and baked strawberries and stir together.
Let this dough chill in the fridge for at least 30 minutes.
Preheat oven to 200C/180C Fan/Gas Mark 6. Line 2-3 large baking trays.
Scoop large balls of cookie dough – somewhere between golf and tennis balls, so you have 8 of similar size. Place on the trays, with several inches in between (max 3 per tray).
Remove the cheesecake filling from the freezer. Create an indent in each ball of cookie dough using your thumb. Place a tsp cheesecake filling into each of these indents, then wrap the dough around so that no cheesecake filling can be seen.
Bake for 12-15 minutes, until golden and crisp at the edges. Repeat for all cookies and leave to cool on a wire rack before serving.