Clean clams by submerging them in a sink full of water. Gently shake the clams every so often. Repeat 2-3 times, until sand is fully removed and water is clear.
Cut zucchini/squash into spaghetti strands using a mandoline or spiralizer. Lightly salt the zoodles and then place them in a colander and let sit for a 1/2 hour. Zoodles will release liquid so put colander in sink or inside of a large bowl. Set aside.
Place a large pan over medium heat and add olive oil.
When the oil is hot, add garlic and shallots. Cook for 2 to 3 minutes or until the shallots are translucent.
Next add red pepper flakes (if using) and wine. Season with salt and pepper. Increase the heat, bring to a boil, then reduce heat to low. Simmer until the sauce is reduced by about half, approx 5 minutes.
Then add butter (if desired) and cook until melted.
Carefully transfer clams to the sauce and cover. Steam for 7 to 10 minutes, until clams open. Discard any clams that don’t open after 10 minutes.
To avoid creating a watery sauce/broth, it is VERY IMPORTANT to use paper towels or a dishcloth to squeeze out and remove excess liquid from the zoodles before adding the clams and sauce to them. Also, there's no need to cook the zoodles because the hot clams and sauce will "cook" them.
Once clams open, ladle them onto the zoodles, then spoon on as much broth as desired and top with chopped parsley. Season with salt and pepper. Serve with lemon wedges, if desired.