1. Using an electric stand or hand mixer and a large bowl, lightly beat the eggs. Add the sugar and continue to mix until fully incorporated. Add the vanilla and oat milk and continue to mix until it is fully combined.
2. In a separate bowl, sift the All Purpose Flour, salt, and baking powder.
3. With the mixer on low speed, slowly pour the dry ingredients into the wet. Increase to a medium speed to ensure the mixture is combined. Slowly drizzle in the butter and blend into the batter until smooth. Allow the batter to rest for a few minutes.
4. Plug-in and heat the pizzelle iron according to manufacturer's instructions. Brush the interior with bran seed oil.
5. Drop about 2 Tablespoons of batter onto the center of the iron; more or less may be needed depending on your maker size.
6. Close and press the iron for 10 seconds, careful not to burn yourself. Bake for 40 seconds or until steam is no longer coming out of the iron.
7. Carefully remove cookies from the iron using heat-safe tongs. Allow to cool completely on a rack.
8. Repeat steps 5 through 7, oiling your pizzelle maker as needed, until you have 24 pizzelles.
9. Using a sharp knife and cutting board, place a pint of ice cream on its side. Carefully slice along the length of the packaging and remove it. Then, cut the ice cream into 1/2-inch wide discs.
10. Optional, you can roll the outer edge each ice cream disc in chocolate or candy.
11. Lastly, place the ice cream disc on top of a pizzelle, then add a second pizzelle on top. Repeat until you have 12 sandwiches. Serve immediately.