I saw this method from a James Hoffman video referencing a technique from the CocktailChemistry channel.

Recipe:

1.5oz bourbon 3/4 oz sweet vermouth 1/4 oz allspice dram 1 dash angostura bitters 1 dash black walnut bitters 7g freshly ground coffee Grapefruit peel

1. Add liquid ingredients to mixing glass and stir with ice ~45 seconds
2. Grind 7g of coffee and add to a pour-over dripper
3. Strain chilled cocktail into the dripper and stir gently
4. Pour into chilled coupe and express grapefruit peel over top