Krispy Kreme uses potato flour NOT bread flour.

All purpose flour works fine……just a little airier with bread flour.

A LiveStrong article has this to say (http://www.livestrong.com/article/557311-how-to-convert-all-purpose-flour-to-bread-flour/) :

The only consistent advice about converting all-purpose flour to bread flour is that you have to add some wheat gluten (aka vital wheat gluten – all major grocery stores should carry this in the baking/spice aisle). The problem is that no one agrees on an amount. The Red Star Yeast company suggests adding 1 teaspoon of vital wheat gluten to 1 cup of all-purpose flour; Cook’s Thesaurus recommends 2 teaspoons of gluten per 1 cup of flour; TipNut.com recommends adding 1 tablespoon of gluten to an unspecified amount of all-purpose flour; and Better Homes and Gardens suggests 1 to 3 tablespoons of gluten per recipe. The amount of gluten all-purpose flour already has can vary, so before you add more it is probably a good idea to bake some test recipes. Start adding small amounts of gluten to the tests to see how they work out. Unfortunately, this will be a trial-and-error process.