Preheat oven to 350°. Line large cookie sheets with parchment paper. Sift together your flour, baking powder, salt and cinnamon. Place butter and sugar in a mixing bowl and beat with electric mixer until smooth and fluffy. Beat in the egg. Add one half of the flour mixture, then the milk and then the remainder of the flour mixture. Gently stir in the oatmeal and raisins. Spoon and shape 24 mounds of batter on the cookie sheets making sure to allow room for them to spread. Bake in preheated oven for 10 to 12 minutes until baked through. Cool for 5 minutes on wire racks and then gently remove the cookies and allow to complete cooling. Place the cream cheese and butter in a mixing bowl and beat until well blended. Beat in the maple syrup, cinnamon and confectioners’ sugar until smooth. Spread the filling over one flat side of the oatmeal raisin cookie, top with another cookie, flat side down and now you have your whoopie pies!