Line 1 or 2 baking sheets with parchment. Carefully lift your pop tarts onto the parchment and finally seal each one with the tines of a fork. Finally brush the tops with beaten egg and prick with a fork to let the steam escape.
Put the trays into the fridge and chill, uncovered for 30 minutes.
Preheat your oven to 210ºc/190ºc fan, bake the Pop tarts for 18-20 minutes, but keep a close eye on them from 15 minutes.