1. Place the Gusto Flexy Soft Bread and dry yeast into the mixer. 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 ingredients are combined, increase the mixer speed to high and knead for 7–8 minutes until the dough becomes smooth, elastic, and does not tear easily.
5. Round the dough, then let it rest for approximately 10 minutes.
6. Divide the dough into 10 g portions, round each piece, then let them rest for 10 minutes.
7. Flatten the dough, add filling according to preference, then shape as desired. Arrange on a 60 × 40 × 3 cm baking tray that has been 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 an oven with top heat of 200°C and bottom heat of 200°C for 10–12 minutes. After that, remove the buns from the oven, brush the surface with egg, then bake briefly again until the surface turns golden brown.
10. Once baked, remove the buns from the oven and cool them on a cooling rack before packaging or serving.