In the bowl of a food processor, combine the cashews, lemon juice, and miso. Process until mostly smooth, adding in non-dairy milk as needed to keep the mixture moving. Add the tofu and dried Italian seasoning, and pulse a few times, until mostly blended but not completely smooth – a bit of texture is desirable. Set aside until needed, or refrigerate if making in advance.

Preheat the oven to 425°F, and line a baking sheet with parchment. Toss together the butternut squash cubes, olive oil, and maple syrup in a large bowl, then spread evenly on the baking sheet. Sprinkle generously with salt and pepper, then transfer to the oven and bake for 25 to 30 minutes, until the squash is tender and starting to caramelize. Allow to cool at room temperature until needed, or refrigerate if making in advance. (If making ahead, allow to come to room temperature before assembling crostini.)

To serve, spread a generous tablespoon of the cashew-tofu ricotta on a baguette slice, top with a few cubes of butternut squash, and arrange a sage leaf on top. Serve immediately.