I love to have something for guests to nibble on while they're waiting for the main event, and these crostini are full of delicious fall flavors. You can do most everything the day before--just save the assembly for the day of!
Preheat the oven to 450 degrees F. On a rimmed baking sheet, toss the squash with the oil and 1/2 teaspoon salt. Spread the squash pieces evenly on the tray and roast for 35 minutes, stirring halfway through, until the squash is cooked and beginning to brown.
In a small saucepan, melt the butter over medium heat. Continue to cook the butter, stirring occasionally, until the solids become golden brown and the butter smells nutty, about 4 minutes. Watch it carefully, as it can go from golden brown to black very quickly. Turn off the heat and allow to cool slightly.
To a medium mixing bowl add the vinegar and 1/4 teaspoon salt. Add the brown butter to the vinegar, using a rubber spatula to get all the browned bits from the bottom of the pan. Whisk to combine. Stir in the basil and the cooked squash and set aside.
Add the sugar and 2 tablespoons water to a small skillet. Place over medium heat undisturbed until the sugar is dissolved. Cook for an additional 6 to 7 minutes until it just barely begins to brown, swirling the pan on occasion to encourage even browning. Stir in the pistachios with a rubber spatula and pour onto a baking sheet lined with parchment paper. Set aside to cool.
In a small bowl combine the goat cheese, mascarpone, and salt with a rubber spatula. Set aside or refrigerate until ready to use.
To assemble, roughly chop the candied pistachios. Divide the cheese mixture on the toast halves. Top each half with a spoonful of the squash mixture, a sprinkle of the candied pistachios, and a few dried cranberries.