Follow these steps to make your own snickerdoodle fudge:

1. Prepare the Baking Dish: Line an 8×8-inch baking dish with parchment paper. This will prevent the fudge from sticking and make it easier to remove and cut.
2. Make the Topping: In a small bowl, mix the sugar and cinnamon for the topping; set aside for later use.
3. Combine Key Ingredients: In a large saucepan, combine the granulated sugar, dairy-free butter, and evaporated coconut milk. Heat the mixture over medium heat.
4. Boil the Mixture: Bring the mixture to a boil and cook until it reaches 234°F-238°F on a candy thermometer, which should take about 5 minutes.
5. Melt the Chocolate: Remove the saucepan from heat, then stir in the white chocolate chips until they are mostly melted.
6. Add Remaining Ingredients: Stir in the marshmallow fluff, vanilla extract, and cinnamon. Mix well until the ingredients are fully incorporated.
7. Pour the Fudge: Pour the fudge mixture into the prepared baking dish, smoothing out the top with a spatula.
8. Apply the Topping: Sprinkle the cinnamon-sugar topping evenly over the fudge, pressing it slightly to adhere.
9. Cool and Set: Allow the fudge to cool for at least 2 hours at room temperature before cutting it into squares.