To prepare the cookies:

1. Preheat oven to 350 degrees F.
2. In a the mixing bowl of a stand mixer fitted with a paddle attachment, cream the butter and sugars on medium speed until light and fluffy. Reduce speed to low, and beat in egg and vanilla.
3. In a medium bowl, whisk together the flour, baking soda, cinnamon, baking powder and salt. Working in portions, gradually beat the flour mixture into the creamed mixture. Using a flexible rubber spatula, stir in the oats and raisins.
4. Arrange two ungreased baking sheets. Set aside.
5. Shape 12-14 dough balls, each about 1 1/4 inches. Place each dough ball onto the baking sheet leaving at least 2 inches between each.
6. Bake until golden brown, about 12 minutes. Cool the cookies in the pans, about 5 minutes. Transfer the cookies to wire racks, and allow to cool completely.

To assemble the ice cream sandwiches:

1. Spread 1/3 cup of ice cream on the bottom of a cookie. Top with a second cookie. Press lightly to flatten. Place the prepared cookies on a baking sheet. Freeze the cookies until firm.
2. Line a baking sheet with a sheet of wax paper. Set aside.
3. Add the chocolate topping to a large bowl. Remove frozen ice cream sandwiches from the freezer. Drizzle chocolate topping over each half of the sandwich, draining excess back into the bowl. Position the dipped ice cream sandwiches onto the prepared baking sheet. Freeze until ready to serve.