Cook 1/3 cup flour and 1 cup water in a small saucepan over medium heat, whisking constantly, until a thick paste forms (almost like a roux but looser), about 5 minutes. Remove from heat and add cream (or milk) and honey. Whisk till dissolved.

Transfer mixture to the bowl of a stand mixer fitted with a dough hook (note: make sure the flour mixture isn’t too hot for the yeast – it should be between 100 to 115 degrees F.) and add milk powder, yeast, kosher salt, 2 eggs, and 5 cups flour.

Knead on medium speed until dough is smooth, about 5 minutes. If the dough is climbing up the dough hook, add water, about a teaspoon at a time. If the dough is not forming a ball, add flour, a teaspoon at a time.

Add butter, a piece at a time, fully incorporating into the dough before adding the next piece, until the dough is smooth, shiny, and elastic, about 4 minutes.

Coat a large bowl with non-stick spray and transfer dough to bowl, turning to coat. Cover with plastic wrap and let rise in a warm, draft-free place until doubled in size, about 30 minutes to 1 hour.

If making rolls, lightly coat a 6-cup jumbo muffin pans or small casseroles with non-stick spray. Turn out dough onto a floured surface and divide into 6 pieces. Divide each piece into 4 smaller pieces (you should have 24 total). They don’t need to be exact; just eyeball it. Place 4 pieces of dough side-by-side in each muffin cup.
 (No need to shape into balls, although you can.)

If making loaves, lightly coat two 9 x 5″ loaf pans with non-stick spray. Turn out dough onto a floured surface and divide into 4 pieces. Nestle pieces side-by-side to create a row down the length of pan.

If making split-top buns, lightly coat two 13 x 9″ baking dishes with nonstick spray. Divide dough into 12 pieces and shape each into a 4″-long log. Place 6 logs in a row down length of each dish.

Let shaped dough rise in a warm, draft-free place until doubled in size (dough should be just puffing over top of pan), about 30 minutes to 1 hour.

While dough is rising, preheat oven to 375°.

Beat remaining egg with 1 teaspoon of water in a small bowl to blend. Brush top of dough with egg wash and sprinkle with sea salt, if desired. Bake, rotating pan halfway through, until bread is deep golden brown, starting to pull away from the sides of the pan, and is baked through,

22–35 minutes for the small pans of rolls, 50–60 minutes for loaf, or 30–40 minutes for the split top buns. If making buns, slice each bun down the middle deep enough to create a split-top before putting in oven.

When finished cooking, let milk bread cool slightly in pan on a wire rack before turning out; let cool completely or serve warm.

Do Ahead: Bread can be baked 5 days ahead; store tightly wrapped at room temperature.