Brush 1 teaspoon of olive oil on the bottom of a 9 x 13-inch sheet pan or cake pan.
Using your fingers, gently spread the prepared pizza dough to fit the bottom of the pan, working to keep the dough thickness even throughout.
Brush the dough with another teaspoon of olive oil, cover, and allow to rise for about 30 minutes, or until double in size.
Mix together the remaining 3 teaspoons of olive oil, the diced garlic and the fresh chopped rosemary. Set aside until the dough is ready.
Drizzle the rosemary garlic and oil mixture onto the risen dough. Use a pastry brush to gently spread the oil and seasonings so the dough is evenly and fully covered.
Using both hands, push your fingertips into the dough to create indentations throughout.
Bake for 30 minutes or until the focaccia is golden brown, but not too crusted.
Cut and serve warm or at room temperature.