In a large bowl, mix starter, water, and melted butter together until combined.
Add flour and salt to the starter mixture and mix until completely combined.
Next, add the shredded cheese and mix with your hands until the cheese is evenly distributed.
Cover the dough with plastic wrap or a shower cap and allow to ferment on the counter for 12-16 hours or overnight.
Preheat your oven to 350 degrees Fahrenheit and get out a sheet pan.
On a clean counter, divide the dough in half. Pat the dough a bit to flatten it out.
Place one half of the dough between two pieces of parchment. Use a rolling pin to flatten out the dough to about 1/8 inch thickness, or as thin as you can get it. Try to shape it as close to a rectangle as you can.
Now peel off the top piece of parchment paper and place the dough (with the parchment still on the bottom) onto a sheet pan. Cut the dough into 1 inch square crackers. Try to make them as close in size as possible so they all bake evenly.
Using a fork, poke each cracker twice to help the crackers stay flatter.
Repeat steps 7-9 with the other half of your dough.
Bake in the oven for 25-30 minutes or until crispy and golden. Once they are done baking, turn the oven off and crack the door open and leave the crackers to cool in the oven.
Once they are cool, place them in a glass jar and enjoy!