Melt the butter in a medium heavy saucepan over medium heat. Add the onions and saute until translucent, 5 minutes. Add the corn and saute another 5 minutes. Add the thyme and garlic and saute until fragrant, 1 minute. Add in the chipotle chiles and zucchini and cook over medium-low heat until the flavors incorporate, 5 minutes. Stir in the flour. Add the cream and bring just to a simmer; stir in the adobo sauce. Season with salt and pepper and remove from the heat.
Preheat the broiler to high.
For assembling the lasagna: Spread about one-quarter of the zucchini-corn mixture over the bottom of a large gratin or 9-by-13-inch baking dish. Top with the ravioli in an even layer. Pour over the remaining zucchini-corn mixture. Top with the cheese.
Broil until the top is browned and bubbly, about 8 minutes.