Place yogurt in a small bowl. Place broken up chocolate in a microwave safe measuring cup and heat in microwave in 30-second increments until it is melted, about 1 to 1-½ minutes.
Add melted chocolate to yogurt and stir well.
Mash raspberries in small bowl and add Grand Marnier if using.
Place enough granola in the dish to cover the bottom.
Spoon or use sandwich bag as noted below to add a layer of chocolate yogurt.
Next add a layer of whipped cream followed by raspberries.
Continue with 2 more layers of all ingredients and end with a topping of whipped cream.
Place a whole raspberry on top and a little shaved chocolate if desired.
Notes
One little trick for putting this trifle together so as not to get too much of the ingredients on the sides of the glass is to use a sandwich bag and snip a hole in one side and squeeze the chocolate yogurt into the middle of the glass.