Preheat oven to 375°. In a blender or food processor, whirl miso, ginger, sake, vegetable oil, rice vinegar, soy sauce, and brown sugar.
In a large bowl, toss squash slices with miso mixture to coat thoroughly. Lift slices from sauce and arrange them, overlapping slightly, on a large baking sheet. Reserve sauce.
Bake 15 minutes. Brush slices with remaining sauce (you will have some left over) and cook until tender when thick edges are pierced with a fork, about 5 to 10 more minutes. Drizzle with sesame oil and serve hot or warm.
*Find white miso in the refrigerated area of your supermarket's produce section.
Note: Nutritional analysis is per serving.