In a small saucepan over medium heat, melt the butter
Let it cook, swirling occasionally, until it foams, smells nutty, and turns a deep golden brown
Immediately stir in the maple syrup (it will bubble, that's normal)
Add the salt and whisk until smooth
Let it simmer together for 1–2 minutes so the flavors meld, then remove from heat
Stir in vanilla if using
Pour into a jar and let cool slightly, it thickens as it sits
Add 1–2 tablespoons to hot coffee, lattes, or cold brew
