Line a junior loaf pan with parchment. Link in the recipe notes.
Mix oat flour, almond flour, maple syrup and vanilla. This should resemble cookie dough, if too sticky add a pinch more flour, if too wet add a drop of water and mix again.
Fold in chocolate, press into pan, freeze to set, about 1 hour.
While the ice cream softens, cut your cookie layer into two.
In the loaf pan make a big square sandwich with two layers and ice cream.
Freeze to set another hour or so, slice, and enjoy (keep frozen!)
Notes
Here are the 3.75 x 5 inch pans I like to use for my mini-batch bar recipes. You can use any small pan and slice differently, or use muffin tins and make 4 single-serving cups.