1. Combine frozen blueberries, lemon juice, vanilla extract, water and xylitol in a small pan over medium heat. Bring to a boil and simmer for around 3 minutes. Take the mixture off the heat and set aside to cool down.
2. In the meantime, to make it easier and mess-free to fill the popsicles with yoghurt, place the coconut yoghurt in a ziplock bag, snip a little corner of the bag with scissors and set aside.
3. Using a spoon, scoop the cooled blueberry mixture into the popsicle moulds quarter of the way up.
4. Now fill the lolly moulds with coconut yoghurt all the way up by gently squeezing the yoghurt from the ziplock bag.
5. Using a lolly stick, gently mix the blueberry mixture with yoghurt inside the popsicle moulds.
6. Insert the lolly sticks in the centre of each popsicle mould, cover with a lid and place to set in the freezer for at least 4 hours. Tip: when you take the popsicles out of the freezer, let them thaw for around 5-7 minutes before removing them out of the moulds. This way they will just ease out of the moulds without much force.