Step 1

Preheat the oven to 450 degrees F (230 degrees C). Line a baking sheet with parchment paper.

Step 2

Whisk 1/4 cup water and flaxseed meal together in a large bowl. Let sit for 5 minutes.

Step 3

Place a steamer insert into a saucepan and fill with water to just below the bottom of the steamer. Bring water to a boil. Add cauliflower, cover, and steam until fall-apart tender, 3 to 6 minutes. Let cool, at least 10 minutes.

Step 4

Grind oats, rosemary, 1/2 teaspoon salt, and 1/4 teaspoon garlic powder together in a food processor until flourlike in texture.

Step 5

Place cooled cauliflower in a fine cheesecloth and squeeze out as much moisture as possible. Add pressed cauliflower to the bowl with the flaxseed-water mixture and stir well. Stir in the oat mixture. Form dough into a ball and place onto the lined baking sheet.

Step 6

Press dough ball down into a circle. Lay a sheet of parchment on top and roll dough flat using a rolling pin to about 1/4-inch thick.

Step 7

Bake in the preheated oven until crust is set, about 15 minutes. Remove from the oven; leave oven on.

Step 8

Place cashews into a pot with water to cover; bring to a boil. Reduce heat to medium-low and simmer until soft, about 15 minutes. Drain.

Step 9

Puree boiled cashews, 1 1/4 cups fresh water, tapioca starch, nutritional yeast, cider vinegar, 1/2 teaspoon salt, and 1/4 teaspoon garlic powder in a blender. Pour puree into a saucepan over medium heat. Cook, stirring continuously, until thickened, about 5 minutes.

Step 10

Heat olive oil in a saucepan over medium-high heat. Saute garlic until fragrant, about 2 minutes. Add crushed tomatoes, balsamic vinegar, maple syrup, 1 teaspoon salt, red pepper flakes, oregano, and black pepper. Simmer marinara sauce until flavors blend, about 10 minutes.

Step 11

Fill blender halfway with marinara sauce. Cover and hold lid down with a potholder; pulse a few times before leaving on to blend. Pour into a bowl. Repeat with any remaining marinara sauce.

Step 12

Spread marinara sauce over the cauliflower crust; top with the 'mozzarella cheese' and add cherry tomatoes.

Step 13

Bake in the hot oven until sauce is bubbling and crust is golden brown, about 8 minutes. Top with basil.