01 -
Add the sweet potatoes to a large stockpot and cover with water. Cover the pot with a lid and bring it to a boil. Cook the sweet potatoes until fork tender, about 15 to 18 minutes. Drain the sweet potatoes and set them aside to cool while you prepare the crust.
02 -
Preheat your oven to 350°F (180°C / gas mark 4).
03 -
Line the bottom and sides of an 8-inch (20 cm) square baking pan with parchment paper, allowing some overhang on the sides.
04 -
In a mixing bowl, stir together the graham cracker crumbs, sugar, and melted butter until combined. Press the mixture evenly into the prepared baking pan.
05 -
Bake the crust for 15 minutes.
06 -
While the crust is par-baking, mix the filling. Add the cooled sweet potato chunks, sweetened condensed milk, softened butter, eggs, spices, and orange zest to a large mixing bowl. Beat with a mixer until the sweet potatoes are mashed and everything is well combined.
07 -
Pour the filling over the pre-baked crust and return the baking pan to the oven. Bake for 35 to 45 minutes, or until a skewer inserted in the middle comes out clean.
08 -
Let the bars cool to room temperature. Then place them in the fridge to chill for 4 to 5 hours, or until completely cool and firm.
09 -
Sprinkle the mini marshmallows on top of the bars. Broil for 2 to 3 minutes until browned and slightly melted.
10 -
Using a sharp, serrated knife, cut into squares and serve.