Toss 1/2 cup cherry tomatoes with olive oil, salt and pepper. Roast on a preheated baking sheet at 425˚ F until softened, 10 minutes. Meanwhile, melt 2 teaspoons butter in a skillet over medium heat. Add 2 sliced scallions (light parts only) and 1 minced garlic clove; cook 1 minute. Add 2 teaspoons flour and stir 30 seconds. Add 2/3 cup milk, 1/2 teaspoon Dijon mustard, 1/2 teaspoon kosher salt and a pinch of cayenne and whisk until thickened, 2 minutes. Off the heat, whisk in 1/3 cup shredded cheddar; set the sauce aside. Sauté 1 pound zucchini noodles in olive oil over medium-high heat until softened, 2 to 3 minutes. Season with salt and pepper. Add to the cheese sauce and cook, tossing, until coated. Top with the roasted tomatoes, chopped cooked bacon and sliced scallion greens.