2Spread butter onto 1 side of each baguette slice.
3Mix avocados, tomatoes, and onion in a bowl until smooth and consistent in texture; scoop onto butter-side of baguette slices. Sprinkle mozzarella cheese over avocado mixture layer. Arrange baguette slices on a baking sheet.
4Bake in the preheated oven until cheese is melted, about 7 minutes.
Footnotes
Cook's Note:
Any variety of cheese can be substituted for the mozzarella cheese.