Preheat oven to 400°F with a rack in the center. Slice baguette on the bias into 1/4-inch thick slices and brush with two tablespoons of the olive oil. Bake until lightly toasted, about 10 minutes.
Meanwhile, warm butter and remaining two tablespoons olive oil over medium-high heat in a large pan. Add sage and thyme and cook for a minute, stirring frequently, until fragrant. Butter will brown. Add squash, salt and pepper and cook, stirring only occasionally, until squash is lightly browned in lots of spots, 5 to 10 minutes. Stir in walnuts and transfer pan to oven. Roast until squash is very tender and will fall apart when stirred, about 20 minutes. Remove from oven and stir in sherry vinegar.
Spread some ricotta onto each toast and top with some butternut squash mixture. Press a few pomegranate seeds into squash mixture. Drizzle with balsamic glaze and sprinkle with flaky salt. Serve warm or at room temperature
Cut butternut squash into cubes of 1/2 inch or smaller so it will cook quickly and evenly.