To prepare crust, combine first 3 ingredients, tossing with a fork until moist and crumbly. Gently press mixture into bottom of a 7-inch springform pan coated with cooking spray.
To prepare filling, beat 1 block fat-free cream cheese and 1/3-less-fat cream cheese with a mixer at medium speed until smooth. Add remaining 1 block fat-free cream cheese; beat until blended. Add 2/3 cup sugar and flour; beat well. Add eggs, 1 at a time, beating well after each addition. Stir in almond extract. Pour batter over crust in pan.
Pour 1 cup hot water into bottom of a 5-quart electric slow cooker. Place a rack in slow cooker (rack should be taller than water level). Place pan on rack. Place several layers of paper towels over slow cooker insert. Cover and cook on HIGH for 2 hours or until center of cheesecake barely moves when pan is touched. Remove lid from slow cooker; turn off heat, and run a knife around outside edge. Let cheesecake stand in slow cooker 1 hour. Remove cheesecake from slow cooker. Cool to room temperature in pan on a wire rack. Cover and chill at least 6 hours. Cut into wedges. Garnish with raspberries, if desired.
To prevent the pan from touching the bottom of the slow cooker, you'll need a small rack that fits inside your cooker. If you don't have one, make a ring out of aluminum foil.