For batter, place the first 9 ingredients in a blender or food processor. Cover and process until smooth. Refrigerate for 1 hour.
Meanwhile, in a large bowl, beat cream cheese and sugar until light and fluffy. Beat in sour cream and vanilla. Fold in creme de cacao and whipped topping. Cover and refrigerate for at least 1 hour.
For the fudge sauce, in a large saucepan, melt chocolate chips and butter over low heat. Stir in sugar and cream. Bring to a boil. Reduce heat; simmer, uncovered, for 10 minutes. Set aside and keep warm.
Heat a lightly greased 8-in. nonstick skillet; pour 2 tablespoons batter into center of skillet. Lift and tilt pan to evenly coat bottom. Cook until top appears dry; turn and cook 15-20 seconds longer. Remove to a wire rack. Repeat with remaining batter, greasing skillet as needed. When cool, stack crepes with waxed paper or paper towels in between.
Spoon 1/4 cup filling down the center of each crepe; roll up. Top with fudge sauce. Sprinkle with mint candies if desired.