Preheat oven to 450° F.
Slice the zucchini into 1/4 inch discs and place them into a large bowl. Add 1 tsp of salt and set aside for 15 minutes.
After 15 minutes, squeeze the liquid out of the zucchini and place them onto a baking sheet. Do not overcrowd the sheet and make sure they are in one layer (use two sheets, if necessary). Drizzle with 2 tbsp of extra virgin olive oil.
Place in the oven and bake for 12 to 13 minutes. Flip and cook for 2 more minutes. Allow the zucchini to cool while you prep the rest of your ingredients.
Begin cooking spaghetti until al dente. In the meantime, chop up your garlic and parsley.
In smaller container (I used a steel pot), add 2 tbsp of the baked zucchini, 2 tbsp of cannelini beans, and 4 tbsp of the water you're cooking you're pasta in. Blend with an immersion blender to create a paste.
In a large sautee pan, add 1 tbsp of extra virgin olive oil over medium high heat. Add the garlic (I also added some garlic peel which I removed before adding the rest of my ingredients). Allow the garlic to cook in the oil for about 2 to 3 minutes, until the edges turn brown.
When the pasta is just slightly undercooked, add it to the pan with the garlic. Add in the the cooked zucchini, the zucchini + bean paste, 1 cup pasta water, the rest of the cannelini beans, the grated parmesan cheese, as well as salt and pepper, to taste. Stir everything together over low heat.
Remove from heat and add parsley, butter, and another drizzle of olive oil before serving.