PLACE ricotta cheese, sugar and almond extract in food processor; cover. Process until smooth. Set aside.
SPRINKLE gelatine over cold water in saucepan; let stand 1 to 2 min. Cook on low heat until gelatine is completely dissolved, stirring constantly. With food processor running, gradually add gelatine to ricotta mixture through feed tube at top of food processor, processing until well blended. Spoon into medium bowl. Reserve 1 Tbsp. of the chocolate chips for garnish. Add remaining chocolate chips and the yogurt to ricotta mixture; stir gently. Refrigerate 30 min. or until thickened.
SPREAD 2 Tbsp. of the ricotta mixture onto each graham square. Stack grahams. Stand on edge on serving platter to make a 14-inch loaf. Frost with the whipped topping. Top with the reserved 1 Tbsp. chocolate chips. Refrigerate at least 4 hours or up to 24 hours. Cut diagonally into 14 slices to serve. Serve leftover dessert in refrigerator.