To a small bowl, whisk together the dry ingredients: all-purpose flour, whole wheat flour, cocoa powder, baking soda and salt. Set aside.

Whip together the butter and brown sugar with a hand mixer until mixed. Add the sourdough discard and honey. Mix until light and fluffy. Add the vanilla extract and mix together again.

Pour the dry ingredients on top of the wet ingredients and mix together with the hand mixer until the dough clumps together. If the dough is crumbly, add a little bit of milk until the dough comes together. It should not be sticky but will clump together to form a ball. If the dough is sticky, add a little more flour until it clumps together.

Shape the dough into two equal sized discs. Wrap in plastic wrap and chill for 1 hour or up to 24 hours.

Preheat oven to 375ºF. Line a half sheet pan (18 by 13 inches) with parchment paper. Take the first disc of dough and roll out on a floured countertop to about 15 by 11 inches. If the dough sticks, add more flour to the bottom and top. Use a biscuit cutter for round crackers or a pizza cutter for rectangles. Cut the dough into 12 equal pieces. Place each cracker on the baking sheet. Take a fork and pierce the dough a few times on each piece. Repeat with the other disc of dough.

Bake crackers at 375ºF for 12-15 minutes until crisp on the edges. Let the crackers cool completely before enjoying!