In a small bowl or measuring cup, activate the yeast using warm water, instant yeast and a pinch of sugar (approximately 1 teaspoon) to help feed the yeast, and then set aside. Yeast mixture will become frothy.
Next add softened butter, the remaining sugar, sweet potato puree, eggs and sea salt flakes to your stand mixer. Cream ingredients until well combined.
Whisk together flour and milk powder and gradually spoon it into your wet mixture with the mixer turned on. Add in activated yeast mixture after adding in few spoonfuls of the flour mixture. Continue gradually spooning in the flour until it has all been added. Mix until well combined and switch the paddle attachment to the dough hook.
Continue kneading the dough for 15-20 minutes using your stand mixer and the dough hook attachment. Cover the mixing bowl with plastic wrap and towel, and let it rest in a warm area for 1 hour.
After an hour, grease a rectangle baking dish (or use baking spray) and roll out dough balls into equal portions. Weigh them to equal weight or divide the dough in 3 large sections. Then divide each large section into 5 pieces. Roll the pieces into round balls and place in evenly spaced rows in the baking dish. Cover the baking dish and leave them to rise for another hour.
Preheat oven to 375°F roughly 15 minutes before the dough has completed the second rise.
While the dough completes its rise, whisk melted butter, dijon mustard, honey, sea salt flakes, onion powder, and granulated garlic until combined. Once the rolls have completed the second rise, uncover and lightly coat them with honey mustard glaze using a pastry brush.
Bake at 375°F for 15 minutes or until rolls have reached an internal temperature of 190°F. Rolls will be a deep golden color when ready.