Preheat the oven to 350°F. Brush the baguette slices with 2 Tbsp. of the olive oil. Arrange on a baking sheet and bake until crisp, 7-10 minutes.

In a large skillet, heat the remaining 1 Tbsp. olive oil over medium heat. Add the mushrooms and sauté until browned, about 3 minutes. Add the wine and sauté until almost dry, about 3 minutes. Stir in the butter, shallots, and thyme and sauté until butter is browned and shallots are translucent, about 3 minutes. Season with salt and pepper to taste.

Spread each crostini with 1 tsp. of the fromage blanc or ricotta and top with an equal amount of the mushroom mixture. Arrange 3 crostini on each of 6 small plates and serve.