In a small bowl mix together oil, sugar and egg. Beat until fluffy. Stir in molasses. Set aside.

In large bowl sift together flour, salt, baking soda, cinnamon and ginger. Stir wet ingredients into dry ingredients until combined. Cover with plastic wrap and refrigerate for 8 hours or overnight.

Preheat oven to 350 degrees. Line a baking sheet with parchment paper.

Remove dough from refrigerator. Roll dough into 1 1/2 - 2 inch size balls depending on how big you want your ice cream sandwiches. Roll the ball into a small bowl of granulated sugar. Place balls on parchment lined baking sheet about 3 inches apart. (cookies will spread so definitely space them out) Bake for 8-10 minutes until edges are set and tops are crackled. Cool on baking sheet for 1 minute then transfer to wire racks to cool completely.

To assemble the sandwiches take the ice cream out of the freezer to soften for 5 minutes. Arrange sprinkles in small shallow bowls. Lay one cookie bottom side up on a flat surface. Place a scoop of ice cream on center of cookie and top with another cookie. Gently press down so the ice cream spreads to the edges of the cookie. Hold the sandwich over the sprinkle bowl and sprinkle some sprinkles onto the ice cream or you can roll the sandwich right in the bowl of sprinkles. Immediately place the sandwiches on a tray and into the freezer.