In a quart-sized mason jar, add heavy whipping cream.
Place the lid on tight and shake until the mixture turns thick and fluffy.
Continue shaking until the mixture returns to liquid again and butter begins to form inside of the liquid. (see notes)
Pour off the liquid. (You can save the liquid and use for baking if desired)
Place the butter in a bowl and rinse with ice cold water until the water runs clear. (use a rubber spatula to press the butter up against the wall of the bowl as you pour off the water).
Once all the water has been rinse off, place the butter in the fridge until it is firm but still creamy, about 10 minutes.
Add in remaining ingredients. (You may need to pour off any extra liquid)
The butter is now ready to use! You may place it in the fridge if you prefer it to be firmer.