Cut potatoes in half, lengthwise, then into thirds. Place into a large mixing bowl.
In a small mixing bowl, whisk together miso paste, brown sugar, cinnamon, syrup, salt, pepper, coconut oil and warm water. The mixture will resemble a thick caramel. Pour over the potatoes, stir to coat, then let sit for 10 minutes.
Line a baking sheet with parchment paper. Give potatoes one more toss in the miso-caramel sauce and then pour them onto the baking sheet. Arrange cut side down.
Bake for 20 minutes, then with tongs, flip potatoes over to the second side and bake an additional 10 minutes or until they are golden and the miso-caramel has thickened.