In a medium glass or ceramic bowl, combine the yoghurt and the mashed fruit. Cover bowl and freeze for 1 hour, stirring every 20 minutes. Spoon the mixture into snack-size, sealable plastic bags, filling them about halfway. Squeeze out the air and seal the bags tightly, then place them in the freezer. When ready to eat, take out of freezer, snip a small piece from one corner of each bag with scissors, then squeeze out the yoghurt for a cool treat.

Makes 4 treats.