For the crostini: Lay the baguette slices on a baking sheet. Brush with the oil and then sprinkle with the salt, garlic powder and some fresh pepper. Bake for 15 minutes, rotating the pan halfway through. Remove the crostini from the oven and set aside. Turn the oven to broil.
For the dip: In medium bowl, combine the ricotta with salt and pepper to taste. Mix until fully combined, then transfer to an 8-by-8-inch pan, spreading the mixture evenly across the bottom. Set aside.
In a large pan with a lid, heat the oil over medium heat. Add the onions, and sweat for 3 to 5 minutes. Add the halved grape tomatoes, chicken stock and garlic and bring to a boil; cover and reduce the heat to low. Cook until the tomatoes have softened and the mixture has thickened, about 15 minutes.
While the tomatoes are cooking, add the sausage to a saute pan over high heat. Break up sausage with a wooden spoon and cook it through. When the sausage is finished, spoon it directly over the ricotta and spread it out evenly.
When the tomatoes are done, spoon them over the sausage layer. Top the tomato layer with the sliced pepperoncini, marinated artichokes and roasted peppers. Place the halved ciliegine on top.
Place the dip under the broiler and broil on high heat until the cheese has browned slightly, 2 to 3 minutes.
Remove the dip from the broiler and top with the basil. Serve immediately with the crostini.