Finely grate the mozzarella using a block or rotary grater
Using a blender of food processor finely blend the tomatos.
Add the cheese, softened butter, and sourdough discard to a food processor and pulse a few times to blend completely then add the tomato blend (or if you are like me, mix it in a bowl or with a hand mixer)
Mix the dry ingredients in a separate small bowl. Flour, baking powder, herbs and spices,
Add dry ingredients and cheese mixture together until completely combined and a dough ball forms.
Roll the dough into a ball and then flatten into a disc between two sheets of parchment paper.
Let the dough rest for about 3o minutes and up to 24 hours in the fridge
Preheat the oven to 350ºF (177ºC)
Roll the dough in between two pieces of parchment paper into a large thin sheet, about 1/16" thick, if you like them a little thicker 1/6" is good
Use a pizza cutter or pastry wheel to cut out 1" squares. Make a whole in the center with a small hole with the wooden dowel or I like to use a small metal straw.
Separate the crackers, place them on a baking sheet lined with parchment paper.
Bake one sheet at a time for 17-20 minutes or until the crackers are turning dark orange and crispy. Thinner crackers will bake faster and thicker crackers will need longer (watch them closely at the end)
Cool on the piece of parchment or a wire cooling rack and bake the rest.
Enjoy!