Preheat your Irish coffee mug by filling it with warm water and letting it warm up the glass. Pour out warm water before adding coffee.

Pour brewed coffee into a warmed mug.

Add Irish whiskey and brown sugar. Stir until the sugar is dissolved.

Use a whisk to slightly whip the heavy cream until it is bubbly and still pourable.

Gently pour the cream over the back of the spoon on top of the coffee.

If desired, you can whip the heavy cream until it is firm and dollop it onto the coffee.