To the bowl of a stand mixer, add the warm milk (make sure this is the temperature of a baby's bathwater…so as not to kill the yeast), melted butter, sugar, yeast and salt.
Add the cornstarch and 2 3/4 cups of flour to the center of the bowl. Knead using the dough hook. Alternatively you can mix the ingredients together in a bowl and knead the dough on your countertop by hand for about 10 minutes. If using a dough hook, knead the dough for about 8 minutes, adding the extra half cup of flour as needed. You should be able to pinch off a chunk of dough, roll it into a ball in your fingers with just a little sticky residue left behind. You can check out this blog post for how to check for readiness of dough if you need some guidance. Line a baking sheet (my favorite here, affiliate link) with parchment paper. Turn the dough out and cut into 12 equal pieces.
Mix together the cinnamon and sugar in a small bowl. Melt the butter in another small bowl. Take a piece of dough and stretch it into a small circle with your fingers. Dip a marshmallow into the butter and then into the cinnamon/sugar mixture. Place the marshmallow into the center of the dough and pinch the dough around the marshmallow, forming a ball.
Place the dough ball onto the baking sheet and repeat with the remaining pieces of dough.
Cover the dough balls and let rise for about 30 minutes.
Preheat oven to 350 degrees.
Bake until the rolls are lightly golden on top for about 22-25 minutes. Top with melted butter if desired.
Remove rolls to a serving plate and enjoy opening the rolls and finding the “empty” tomb on Easter morning. These rolls are best eaten warm. Enjoy!