Fill an old-fashioned glass with 1 cup ice.
Combine vodka, coffee liqueur, Irish cream, and heavy cream in a cocktail shaker. Add ice; cover and shake until chilled. Strain into the prepared old-fashioned glass.
The mudslide cocktail is like a milkshake on the rocks for grown-ups! Irish cream mixed with coffee liqueur and vodka makes for a frothy, creamy cocktail.