Shell shrimp, then add shells to the white wine and simmer in a small covered saucepan for about 30 minutes. Strain and reduce liquid to about 1/4 cup.
Add spinach to reduced liquid, cover and cook until tender. Allow to cool. In a small saute pan cook bacon until crisp. Remove bacon bits and drippings from pan. Melt butter, then add shallots and garlic and cook until translucent. Add shrimp and spices; continue to cook until shrimp are opaque.
Drain spinach well, reserving liquid. Add spinach liquid, heavy cream and hazelnut liqueur to shrimp mixture and continue to cook until liquid is thickened and reduced by 1/2. Allow to cool.
Then in a medium sized bowl mix spinach with shrimp, bacon and remainder of ingredients (except oysters). Top each oyster with about 2 to 3 tablespoons of the stuffing. Cook on top rack of grill at high heat until mixture is bubbling and golden brown on top.