Makes 36 portions.
Preheat the oven to 350ºF (180ºF). Pierce the sweet potatoes with a fork and bake them until tender, 30-40 minutes. Let them cool completely.
Line mini muffins tins with paper liners. Peel the skin from the cooled sweet potatoes and purée them until smooth. Measure out 1 cup (250 mL) of the purée into in a saucepan along with the brown sugar. Bring this to a simmer over medium heat while whisking, and simmer for about a minute after it begins to bubble. Remove the pan from the heat and whisk in 1/4 cup (60 mL) of the almond butter, until it has dissolved. Transfer this to a large mixing bowl and set aside.
Place the white chocolate, coconut oil and the remaining 1/4 cup (60 mL) of almond butter in a small saucepan and melt until smooth over low heat when gently but constantly stirring. Add this to the sweet potato mixture and whisk in.
Whisk in the icing sugar, vanilla and salt by hand until smooth. Spoon the mixture into a piping bag (with a large plain tip, or even no tip) and pipe the fudge into the paper cups, right to the top. Sprinkle each piece of fudge with the décor of your choice and chill for at least 2 hours until set.
The fudge will keep, refrigerated, for up to 2 weeks.