Remove sausages from package and pat dry with a paper towel. Cut into 1 ½ in pieces, I cut each sausase link into four pieces. Then make slash like cuts on an angle all the way down the length of each sausage but do not cut all the way through. Place these sausages in a baking dish, 9 x 13 is best but you can use a smaller one if it is all you have.
Preheat your oven to 400 degrees
In a bowl combine all of the other ingredients, whisk until smooth and then taste and adjust seasonings. You may want it slightly sweeter and if so, you can add more brown sugar or honey. *This sauce does have a stronger vinegar taste but some of that will cook off as it bakes.
Pour this mustard mixture over the sausages and bake. I baked these about 30 minutes, every oven will bake slightly differently. Pull them when the sausages are caramelized in the sauce. *you may need a longer cook time if you are not using already cooked/smoked sausages
