Melt chocolate either in the microwave (be careful not to burn!) or over a double boiler. Let cool slightly.
Stir in 1 cup sour cream and 1 tablespoon powdered sugar.
Combine remaining sour cream with the rest of the 1/4 cup powdered sugar. Add more to taste.
Layer gluten free tortilla, 1/3 chocolate mixture, tortilla, 1/3 chocolate mixture, tortilla, 1/3 chocolate mixture.
Top with remaining tortilla and spread sour cream mixture on top.
Garnish with shaved chocolate.
Chill for at least 2 hours.
Enjoy!