Preheat Oven: Preheat oven to 400 degrees.
Whisk Ingredients: In a small mixing bowl, whisk together almond flour and salt. Add egg and whisk until well combined.
Melt Cheese Then Mix With Other Ingredients: In a microwave-safe bowl, microwave cheddar, mozzarella, and cream cheese until melted, about 1 minute. Add melted cheeses to dry ingredients and, using hands, knead together until fully incorporated. (If the dough becomes too difficult to work with, return all ingredients to microwave-safe bowl and microwave for 10-15 seconds.)
Roll Out Dough: Spray two pieces of parchment paper with cooking spray. Lay one piece down, spray side up, placing dough in the center. Lay the other piece down, spray side down so it touches the dough, and lightly press down. Using a rolling pin, roll the dough until it is an even layer. The dough should be quite thin. Remove and discard the top piece of parchment paper. Carefully slide a baking sheet beneath the parchment paper with the dough on top.
Slice Crackers and Sprinkle Salt: Using a pizza cutter, gently slice crackers into the desired size. Sprinkle coarse salt to the top of the dough. Optionally, use a fork to crimp all of the edges of the crackers and poke a hole with a skewer in the middle of each to resemble a traditional Cheez-It.
Bake Crackers: Transfer baking sheet to oven and bake crackers for 7 minutes.
Flip Crackers Over and Bake Again: Remove crackers from oven and allow to cool slightly. Using a spatula, flip all crackers over (it may be necessary to re-cut some of the crackers with a pizza cutter as they may have melted together while baking). Return crackers to oven and bake for another 3-5 minutes.
Break Crackers Apart: Remove baking sheet from oven, allow the crackers to cool completely, then serve.