Make the cookies. Preheat the oven to 350°F and line two baking sheets with parchment.
Beat the butter with the sugar until light and fluffy. Add the egg and vanilla and beat until incorporated. Add the flour, baking soda, cinnamon, baking powder and salt and mix well. Stir in the oats and raisins until evenly distributed.
Scoop the cookies into 1 1/2 inch balls (or use a cookie scoop) and place a few inches apart on the baking sheets. Bake for 11-13 minutes, or until lightly golden brown. Remove from the oven and cool completely on cooling racks.
Assemble the sandwiches. Scoop about 1/3 cup of ice cream and place on the bottom of one cooled cookie. Put another cookie on top and press gently to make a sandwich. Place it on a parchment lined baking sheet and repeat until all of the cookies are used. The recipe will make 7-8 ice cream sandwiches. Freeze until solid, about 30 minutes.
Make the chocolate coating. Place the chocolate chips and coconut oil in a microwave safe container. Melt in 30 second increments, stirring between each until the chips are melted. It will take about 1 to 1 minute and 30 seconds to melt. Stir until smooth. Set aside to cool a bit.
When the cookie sandwiches are frozen, remove from the freezer and dip half (or the whole thing depending on your preference) into the chocolate coating and return to the parchment lined baking sheet. When all sandwiches are coated with chocolate, return to the freezer and freeze until solid, about 15 minutes more. Serve immediately, or wrap each sandwich in plastic and store for up to 3 months.