Pre-heat oven to 180 degrees C and grease/line a shallow tin-set to one side.
Whisk eggs and Natvia in a bowl until well combined. Slowly add melted coconut oil whilst continuing to whisk.
Stir in all remaining ingredients and mix well until if forms a thick and cake-like mixture. Pour mixture into tin and even out well.
Bake for 25 minutes; checking after 20 minutes. Remove from the oven and leave to cool in the tin for 1 hour, then remove and leave to cool completely on a wire rack.
Once completely cool you can make the frostingBlend soft cheese, Natvia and softened coconut oil until smooth. Mix in walnuts using a spoon. Spread the frosting over the cake and pop in the fridge for 20 minutes to set. Once ready to serve, remove and cut into squares.
Store in an airtight container in the fridge for up to 5 days