Spread the walnuts out on a parchment-lined baking sheet and roast at 350F for 10 minutes.
In a small pot, mix together the coconut sugar, water, vegan butter and maple syrup. Bring to a boil, then turn the heat down to medium low. Bubble and stir gently for about 8 minutes until it's a deep brown caramel color (225F on a thermometer, or you can try going up to 300F to make walnut brittle)
Remove from the heat and stir in the baking soda.
Stir the walnuts into the caramel, then spread the whole mixture out thinly on the same parchment-lined baking sheet.
Cool completely, then enjoy your treats, or blend into a praline paste to use for patisserie, or store in an airtight container in the fridge.