Preheat oven to 350 degrees. Line a mini muffin pan with muffin cups. Mix together the crushed Oreos and butter until moistened. Press about 1/2 Tbl. of this mixture into each muffin cup. A shot glass sprayed with cooking spray works well for flattening out the crusts evenly.
Cream together cream cheese and sugar. Beat together eggs and Frangelico, then stir into cream cheese mixture. Fold in mini chocolate chips.
Fill muffin cups about 3/4 full with batter. Bake for 15 min. at 350 degrees. They should be slightly soft in the center and not yet brown at the edges.
When cool, spread 1 tsp Nutella onto each cheesecake and sprinkle with toasted hazelnuts.