For the base butter:
Pour cream and salt into bowl of standing mixer with whisk attachment. Place protective shield on the bowl and turn mixer on high. Mix 4–6 minutes. The heavy cream will separate from the milk and clump together, leaving buttermilk at the bottom of the bowl.
Stop mixer and pour off the buttermilk into another container to separate the butter clumps from the milk. You want to keep this milk, as this is pure buttermilk that maybe used for other recipes, such as pancakes or biscuits.
Use a spatula to press out as much milk as possible, drain and repeat. Add about ½ cup of ice water (strain the water to ensure no ice gets into the bowl). Put the shield on the bowl again and cover with a towel. Mix on high for about 30 seconds, drain water and repeat the process until water appears less cloudy. Once you complete this process, you have fresh homemade butter.
Pack the butter in a container and cover tightly. Once you have the base butter you can mix in the flavoring ingredients.
For the honey walnut cinnamon butter:
Mix all ingredients with base butter and chill.
Butter may be refrigerated for up to 2 weeks or frozen for up to 6 months.