In a small bowl, combine ⅓ cup of the boiling water and the mustard seeds. Mix well, and set aside.
In another small bowl, mix the powdered mustard with ⅓ cup boiling water. Whisk until powder dissolves. Set aside for 10 minutes so the flavor can develop.
In a small saucepan, add vinegar, brown sugar, salt, onion powder, garlic powder, cinnamon, allspice, cloves, and maple syrup. Mix together and bring to a boil. Then reduce heat and simmer for 5 minutes.
Mix in both mustard mixtures from step 1 and 2 to the vinegar mixture
Pour mixture into blender and blend on high until mustard seeds are crushed.
Pour mustard into container with a tight fitting lid and refrigerate.
