Preheat oven to 350°F. Lightly coat a 13x9x2-inch baking pan with cooking spray; set aside.
For crust, place oats in a food processor or blender. Cover and process or blend until coarsely ground. In a small bowl combine ground oats, flour, brown sugar, and melted butter. Pat evenly into the bottom of the prepared pan. Set aside.
Meanwhile, for cheesecake filling, in a large bowl combine cream cheese, peanut butter, and granulated sugar. Beat with an electric mixer on medium speed until combined. Add egg substitute, the ¼ cup milk, and the vanilla. Beat on low speed just until combined.
Pour cheesecake filling onto the prepared crust. Bake in preheated oven for 25 minutes or until set in the center. Cool in pan on a wire rack for 30 minutes. Cover with foil and chill for at least 4 hours or up to 24 hours.
For chocolate drizzle, in a heavy small saucepan heat and stir chocolate over low heat until melted and smooth. Remove from heat and beat in enough of the 2 to 3 tablespoons milk to make drizzling consistency. Spoon melted chocolate mixture into a small resealable plastic bag. Seal bag. Using scissors, snip off a very small corner from bag. Pipe melted chocolate over the cheesecake filling. Sprinkle with chopped peanuts. Cover and chill until chocolate is set.
Tip: Choose Splenda Brown Sugar Blend for Baking and Splenda Sugar Blend for Baking. Follow package directions to use product amounts equivalent to ¼ cup brown sugar and ⅓ cup granulated sugar. Per serving with sugar substitutes: 137 calories, 7 g protein, 10 g carb., 8 g total fat (3 g sat. fat), 8 mg cholesterol, 1 g fiber, 2% Vitamin A, 0% Vitamin C, 202 mg sodium, 8% calcium, 4% iron. Exchanges: ½ starch, 1 lean meat, 1 fat Carb Choice: .5