Please choose the correct solution to the question: Make Keto buttercream

Solution1: 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.

Solution2: 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 format: solution1/solution2