Brown the butter

• Melt the butter in a saucepan over medium heat.
• Keep cooking until the milk solids turn golden brown and it smells nutty.
• Pour into a bowl and let it cool slightly.

Make the cookie dough

• Whisk the brown butter with the brown sugar and granulated sugar until smooth.
• Beat in the egg, egg yolk and vanilla extract.
• Fold in the flour, baking soda, salt and chai spice mix until just combined.

Chill the dough

• Cover the dough and refrigerate until firm.

Shape and coat the cookies

• Roll the dough into balls.
• Mix the cinnamon with the granulated sugar and roll each ball in it.
• Place them on a lined baking tray.

Bake

• Bake at 180 °C until the edges are set and the centers are still soft.
• Let the cookies cool on the tray for a few minutes, then transfer to a cooling rack.