Spoon 10 heaped spoonfuls of mincemeat onto a lined tray and freeze for a minimum of an hour - 4+ hours is best.
Preheat the oven to 180ºc fan, or 200ºc regular
Add the butter and sugars to a bowl and beat until creamy
Add in the egg and vanilla and beat again.
Add in the plain flour, baking powder, bicarbonate of soda, and salt and beat until a cookie dough is formed!
Add in the chocolate chips and beat until distributed well
Weigh your cookies out into ten cookie dough balls - they're about 90-100g each
Flatten each portion of cookie dough in your hand, add the mincemeat to the middle and wrap the cookie dough around tightly.
The longer the mincemeat has frozen, the easier this is. Make sure the cookie dough is quite flat so you have enough to wrap around the mincemeat without causing a mess.
Split the cookies between two large trays. Bake the cookies in the oven for 11-13 minutes.
Let the cookies cool on the trays for at least 30 minutes, as they will continue to bake whilst cooling!
Notes
These will last for 3-4+ days at room temp or in the fridge