Heat oven to 400 degrees. Line 12-cup muffin pan with large paper liners.
In large bowl, whisk flour, baking powder, salt and pepper. In separate bowl, whisk 1/4 cup pesto, olive oil, milk, sugar and egg; stir into flour mixture until moistened. Fold in zucchini and green onions.
Divide half the batter evenly among muffin cups; place cube of Fontina on top of batter. Top each with 1 teaspoon remaining pesto; top with remaining batter.
Bake 15-20 minutes, or until golden brown and top of muffin springs back when pressed lightly. Let cool slightly; serve warm.
Tip: To make extra-savory, add 1/2 cup cooked and crumbled bacon.