In a large mixing bowl, combine the warm water, sugar, and instant yeast. Allow the mixture to sit undisturbed for about 5 minutes, or until it becomes frothy. This step activates the yeast.
Add the olive oil, salt, and 2 cups of the all-purpose flour to the yeast mixture. Stir thoroughly until just combined.
Gradually incorporate the remaining flour, one cup at a time, mixing until a soft dough begins to form. Dust your work surface with flour and knead the dough for 5-7 minutes, until it is smooth and elastic.
Transfer the kneaded dough into a greased bowl, cover it with a damp cloth, and place it in a warm area to rise for about 1 hour, or until the dough has doubled in size.
Preheat your oven to 375°F (190°C) while the dough is rising.
Once the dough has risen, gently punch it down to release any air bubbles. Roll the dough out on a floured surface into a large triangle shape.
Using a sharp knife or a pizza cutter, cut the triangle into smaller triangle-shaped pieces, resembling the branches of a Christmas tree.
On the bottom two-thirds of the dough, evenly sprinkle a mixture of mozzarella cheese, Parmesan cheese, garlic powder, and dried Italian herbs.
Fold the top third of the dough down over the cheese mixture, pressing gently to seal the edges.
From the base of the dough, cut vertical strips upward toward the sealed top, leaving about an inch at the top uncut to create the tree’s trunk.
Carefully twist each strip of dough to form whimsical branches of your Christmas tree.
Arrange these twisted dough pieces to recreate the shape of a Christmas tree on a baking sheet lined with parchment paper for easy cleanup.
Beat the egg in a small bowl and brush it generously over the dough to achieve a shiny golden crust. If desired, sprinkle sesame seeds or poppy seeds on top for an extra festive touch.
Bake in the preheated oven for 25-30 minutes, or until the bread is golden brown and sounds hollow when tapped.
Allow the Cheesy Christmas Tree Bread to cool slightly on a wire rack before serving.