1. Place the Gusto Flexy Soft Bread and dry yeast into a mixer bowl. Mix on low speed for approximately 1 minute until evenly combined.
2. Add the ice water, then mix again on low speed for about 1 minute.
3. Add the butter or margarine, then continue mixing on low speed for 1 minute.
4. Once all the ingredients are combined, increase the mixer speed to high and knead for 7–8 minutes until the dough is smooth, elastic, and does not tear easily.
5. Round the dough into a ball, then let it rest for approximately 10 minutes.
6. Divide the dough into 60 g portions, round each piece, then let them rest for 10 minutes.
7. Flatten each dough piece, add the desired filling, then shape as preferred. Arrange on a 60 × 40 × 3 cm baking tray greased with butter or margarine.
8. Proof the dough in a proofing cabinet at 37°C with 60–80% relative humidity (RH) for 1–1½ hours, or until the dough has doubled in size.
9. Bake in a preheated oven at 200°C top heat and 200°C bottom heat for 10–12 minutes. Remove the buns from the oven, brush the surface with egg, then return them to the oven briefly until golden brown.
10. Once baked, remove the buns from the oven and cool them on a wire rack before packaging or serving.