Finish the following sentence with the best choice: Make Keto buttercream

Choices:
- 8 oz. unsalted butter, at room temperature    2 tsp vanilla extract    1½ tsp ground cinnamon    1 - 2 tsp erythritol (optional)    Brown ¼ of the butter in a small sauce pan until it turns amber in color, but without burning it.    Pour the browned butter in a glass of milk and whisk in the rest of the butter bit by bit with a hand mixer until fluffy.    Add cinnamon and optional sweetener towards the end.
- 8 oz. unsalted butter, at room temperature    2 tsp vanilla extract    1½ tsp ground cinnamon    1 - 2 tsp erythritol (optional)    Brown ¼ of the butter in a small sauce pan until it turns amber in color, but without burning it.    Pour the browned butter in a beaker and whisk in the rest of the butter bit by bit with a hand mixer until fluffy.    Add cinnamon and optional sweetener towards the end.

Answer:
8 oz. unsalted butter, at room temperature    2 tsp vanilla extract    1½ tsp ground cinnamon    1 - 2 tsp erythritol (optional)    Brown ¼ of the butter in a small sauce pan until it turns amber in color, but without burning it.    Pour the browned butter in a beaker and whisk in the rest of the butter bit by bit with a hand mixer until fluffy.    Add cinnamon and optional sweetener towards the end.