Melt the coconut oil and peanut butter then pour into the blender along with the Natvia. Pulse a few times to allow the mixture to come together in a slightly sticky flapjack mixture.
Tip ¾ of the mixture into a lined tin or tub (I used 10cm x 20cm) and press down with your fingers in an even layer, being sure to pack in tightly. Chill while you make the jam.
Place the berries in a pan with the Natvia and simmer for 8-10 minutes until softened and the juices have run out. Remove from the heat, mash up well and stir in the chia seeds and vanilla. Leave to stand and cool for 20 minutes - the jam will thicken.
Once cooled, spread this over the base evenly (you don’t want the layer too thick otherwise it will ooze out).
Sprinkle over the rest of the topping to cover then gently press down with the palm of your hand, packing in again. Chill in the fridge for at least 3 hours to set.
When ready to serve, remove from the tin/tub and place on a chopping board. Cut into 10-12 pieces and enjoy!