Step 1

Preheat oven to 375°F. Bring 3 quarts water to a boil in a large saucepan over medium-high. Stir in 3 tablespoons salt, and return to a boil. Add pasta shells; cook, stirring occasionally, until pasta is al dente, about 8 minutes. Drain and rinse with cold water; set shells aside.

Step 2

Stir together marinara, Calabrian chiles, and fennel seeds in a medium bowl. Season with salt to taste. Spray a 13- x 9-inch glass or ceramic baking dish with cooking spray; spread sauce in an even layer in dish, and set aside.

Step 3

Heat 2 tablespoons oil in a large skillet over medium; swirl to coat. Add garlic; cook, stirring constantly, until fragrant, about 30 seconds. Add kale, and toss to coat. Drizzle remaining 1/4 cup water over kale. Cover and cook until kale is tender, about 5 minutes, stirring once halfway through cook time. Add artichoke hearts; cook, uncovered, stirring occasionally, until warmed, about 2 minutes. Remove from heat.

Step 4

Combine beans, spreadable cheese, and remaining 2 tablespoons oil in a food processor; process until smooth and creamy, about 45 seconds, stopping to scrape down sides as needed. Add bean mixture to kale mixture, and stir until well combined. Season with salt to taste.

Step 5

Spoon bean mixture evenly into cooked pasta shells (about 3 tablespoons per shell). Arrange shells on marinara mixture, and sprinkle evenly with provolone. Bake, uncovered, in preheated oven until provolone melts and sauce is bubbly, about 20 minutes. Increase oven temperature to high broil, and broil until cheese begins to brown, 1 to 3 minutes. Serve hot.