Beat Butter. Add softened butter to a large bowl and beat with a hand mixer for 2 minutes, until the butter is lighter in color and fluffier. (Pause to scrape down the bowl a few times, as needed)
Build Flavor. Scrape down the edges of the bowl and add powdered sugar, honey, 1/2 tsp. cinnamon, and vanilla. (If using unsalted butter, add a pinch of salt as well.)
Whip the butter another 2-3 minutes, until it's lightened in color, and it's smooth and creamy. Taste and add more cinnamon as desired. Smooth and stir through with a spatula to make sure everything is evenly combined.
Store. Transfer whipped cinnamon butter to a jar with a lid to store at room temperature 3-4 days, or in the refrigerator up to 1 week. Let chilled cinnamon butter soften at room temperature to use it.
Notes
Soften The Butter First! You want the butter to be softened--cool to the touch, but your finger can create an indent when you press down. You don't want it hard (no indent) or too warm and overly soft (it shouldn't look shiny or greasy + your finger should not sink in easily). Aim for softened! Vegan butter, margarine, or dairy-free butter will not work for this recipe.
Serve: For a pretty presentation, you can add the butter to a piping bag fitted with a piping tip and pipe it into a bowl.