Preheat oven to 375°F/191°C. Grease and line 2 cookie sheets. Set aside.
In a bowl, cream together butter and brown sugar until pale and fluffy. Stir in egg and vanilla until well combined.
Add in the flour, oats, baking soda, cinnamon, salt, and half of the sliced raisins. Mix well.
Scoop batter onto the cookie sheets 1-2 inches apart. Lightly flatten the cookies and sprinkle remaining raisins on top.
Bake for 10-15 minutes or until golden brown on the edges but still soft at the center. Set aside to cool.
Pipe whipping cream on the bottom of one cookie, then top with another cookie.
Serve.
Yield: 6-8 servings