Toss the oysters (reserve the liquor for later) with the Essence in a medium bowl.
Heat the olive oil in a large heavy skillet over medium-high heat. Add the onions and cook until softened, about 3 minutes. Add the cream and barbecue sauce base and boil until reduced by half, about 2 minutes. Add the oysters and their liquor and cook until the edges of the oysters just begin to curl, about 1 1/2 minutes. Remove from the heat.
To serve, put three of the warm biscuits on each plate. Top each with two oysters. Spoon a few tablespoons of the sauce over each serving. Serve hot.
Yield: 4 appetizer servings