Beat the butter and both sugars until pale and fluffy, about 2-3 minutes.
Add vanilla and milk alternative and mix again.
Add the dry ingredients and chopped chocolate and fold together until just combined.
Scoop cookie dough into balls and place on a lined baking tray.
Bake cookies at 170C for 10-11 minutes, rotating the baking tray half way through.
Remove from the oven and sprinkle with some flaky sea salt (optional).