Preheat the oven to 350°F and line a baking sheet with parchment or spray with cooking spray.
Place the tomato slices on a paper towel and sprinkle lightly with salt. Gently press another paper towel on top and allow to sit while you prepare the rest of the ingredients.
Slice the zucchini in half. Cut a small slice from the peel on the opposite to give a solid base and keep it upright while baking.
Mix the melted butter with the garlic salt, onion powder, dry Italian seasoning and blac pepper to your taste.
Brush the tops of the zucchini wit the seasoned butter. Reserve the remaining butter for the crumb topping.
Sprinkle with ½ of the shredded gouda. Arrange 4 slices of tomato on each.
Sprinkle with the remaining shredded gouda cheese.
Toss the panko breadcrumbs and grated Parmesan cheese with the remaining butter and sprinkle over the gouda cheese.
Bake for 30 minutes or until fork tender. Garnish with chopped fresh basil, if desired.