In a large saucepan, melt the butter over medium heat. Whisk in 2 tablespoons flour. Reduce the heat to medium-low and cook for 1 minute, stirring to avoid burning—it will bubble. Gradually whisk in the milk and 1 cup of water, then stir in the macaroni. Increase the heat to medium-high and bring the mixture to a boil. Stir frequently until the macaroni is just al dente, 8 to 10 minutes. If the sauce thicken too quickly, add 1/2 additional water.When the macaroni is al dente, remove the pan from the heat and stir in the cheddar, fontina, Havarti, mustard, and cayenne. Season with salt and pepper. Stir until the cheeses have fully melted. Let cool. Transfer to the fridge to chill 2 hours or place in the freezer 30-45 minutes, until cold. Preheat the oven to 425 degrees F. Line 2 baking sheets with parchment paper.Place the panko, parmesan, 2 tablespoons flour, and the paprika in a shallow bowl. Add the eggs to a separate bowl. Scoop out 1 tablespoon of mac and cheese and pack it into a ball. Sandwich the mac and cheese between 2 zucchini slices, secure with 2 toothpicks. Dredge the stuffed zucchini bites through the egg, and then through the panko mix, tossing to coat entirely. Place onto the prepared baking sheet. Repeat until all the bites are breaded. Make sure not to crowd your pans. Brush/drizzling the bites with olive oil. Transfer to the oven and bake for 15-20 minutes or until golden and crisp. Some of the bite may break in half, it's OK, they will still be delicious. Serve while hot with your favorite dipping sauces and or fresh herbs.