This Prohibition-era classic, updated by Robyn Gray, was named for the hat-shaped Los Angeles diner and originally called a De Rigueur cocktail.
• 2 oz Bakers 7yr Bourbon
• 1 oz grapefruit juice
• 0.75 oz honey syrup (see note)
• 2 tsp lime juice
• Garnish: Grapefruit slice.