Heat oven to 375F. Grease 13x9 in. baking dish with oil. Peel squash, slice in half lengthwise, and remove seeds. Cut into ½ in. slices. Arrange in baking dish w/ slices slightly overlapping each other (scallop pattern).
In a small saucepan, melt butter over low heat, add garlic, and cook until softened and fragrant, about 2-3 min. Stir frequently to avoid burning. In a separate bowl, combine panko, parmesan, walnuts, cranberries, and garlic-butter mixture.
Coat squash slices with oil, season with salt and pepper, and sprinkle panko mixture on top.
Bake for approximately 40-50 minutes. Top with basil and serve.