Overnight Cinnamon Rolls are perfect for breakfast or brunch gatherings! Most of the work is done the day before, on day of serving- rise, bake and frost.
Carefully place eggs (in shells) into a small bowl of warm water to gently heat the eggs. Let sit while preparing yeast mixture. Or use room temperature eggs.
Place warm milk in the bowl of a stand mixer. Sprinkle 1 tablespoon of yeast and 1 teaspoon sugar over the warm milk. Let sit until the yeast begins to bubble and rise.
Add eggs, egg yolk, 4 tablespoons melted butter, oil , 1/3 cup of sugar and salt to the yeast mixture. Mix until blended with paddle in mixer on low.
Add 3 cups all purpose flour. Mix on low until all ingredients are incorporated. Add 1 cup bread flour a little at a time, switch to dough hook. Mix until all flour is mixed in, and no white patches are visible. Mix for about 1 minute on low speed using dough hook. The dough should look smooth when finished.
Lightly coat the inside of mixing bowl with cooking spray. Cover bowl with Saran wrap. Let sit for about 2 hours in a draft free place that is at least 72 degrees.*
While dough is rising, prepare the filling and the pan for baking.
Mix 6 tablespoons room temperature or slightly melted butter, brown sugar, cinnamon and a pinch of salt together in a small bowl. Set aside.
Generously butter the bottom and sides of a 9x13 pan (preferably not glass*) and set aside.
Using a lightly floured surface, pat and then roll the dough into a 20"x10" rectangle.
Spread the filling onto the dough evenly.
Roll up the dough, starting with the long side, until the dough is rolled into one long piece.
Using a sharp knife, pastry scraper with sharp edge or unflavored dental floss, cut the rolled dough into half, then each half into 2 pieces, then each portion into 3 even rolls. You should have 12 rolls when finished (see photos on post)
Place the rolls into prepared pan and cover with a sheet of parchment. Tightly cover the pan with foil or plastic wrap and place in refrigerator for 2-12 hours.
2 1/2-3 hours before baking, place pan on top of dry dishtowel in a warm draft free place.* Do not set pan directly on a cold stone countertop! Remove cover used in refrigerator and parchment. Cover with clean, dry dishtowel. Let come to room temperature and rise. Alternately, you may use a proof setting on your oven (85 degrees) and cover the rolls with parchment and a light towel. Leave the rolls in the oven to raise for about 1 1/2 hours.
30 minutes before baking, heat oven to 375 regular bake OR 350 Convection. Place rack in center of oven. Prepare frosting (below) and set aside.
When rolls are ready to bake, place in oven and bake for 15 minutes (convection) or 375 regular bake for 15-20 minutes or until tops are a light golden color. Remove from oven.
When rolls are still hot, frost with about 1/2 to 3/4 cup of the frosting. This will melt into the rolls a bit, but topping with a portion of the frosting while rolls are hot will allow the frosting to seep into the rolls and create a gooey soft, flavorful roll.
After rolls have cooled about 15 minutes, top with remaining frosting and serve.
While rolls are baking, combine soft cream cheese and butter in a bowl. Mix until smooth. Add powdered sugar, and mix again on low speed. Add milk, vanilla, and dash of salt. Mix until smooth. Add a splash more milk if needed. See notes for make ahead.