Measure out sourdough discard in a mixing bowl. If using only 100g, go to step 3.
Divide total amount of sourdough discard used (if more than 100g) by 100. For example, if using 200g sourdough discard, 200 divided by 100 equals 2. Multiply the other ingredients by the number to increase the recipe in proportion to the amount of sourdough discard used.
Melt butter. Let cool before adding.
Add molasses and brown sugar to the bowl with sourdough discard. Mix ingredients together.
While the butter is cooling, mix the dry ingredients, the flour, spices, baking soda, and salt, together in a separate mixing bowl.
Add the cooled butter to the wet ingredients and stir together. (If using a stand mixer, use the paddle attachment.) Then, add the dry mixture.
Mix all the ingredients together until a dough forms.
The dough can be covered and left to ferment or it can be rolled out and baked right away. Both versions taste great! If you are letting the dough rest and ferment, proceed to step 7 after 1-2 hours (or overnight). I recommend shaping first and covering to ferment.
Cut a large piece of parchment paper (about the size of a cookie sheet). Place about a softball size portion of dough on the parchment paper. Roll out evenly until the dough is about 1/8 inch thick.
Use a rolling pizza cutter or knife to cut the rough edges off dough so it becomes a large square or rectangle. Scraps can be put aside and rolled into another batch. Cut the large piece of dough into 1-inch strips. Turn the dough and cut the strips into small 2-3 inch long rectangles. (Or cut into other unique shapes, see notes below)
Use a fork to poke the rectangles twice.
Preheat oven to 350 degrees.
Bake crackers for 18-24 minutes until they are beginning to harden around edges and tops are matte and not glossy. Don’t overbake, these can go from perfectly baked in just a few minutes.
Allow to cool on cookie sheet.
Repeat steps 8-12 if there is any remaining dough.