Preheat oven to 350°F. Line a 7x5 pan with a strip of parchment paper (leaving some paper out the top for "handles") and coat the sides in coconut oil.
In a saucepan bring all filling ingredients to a boil except the baking soda. Once boiling, add the baking soda, reduce heat to a simmer and cook for 5 minutes or until the dates are falling apart. Remove from heat and let slightly cool.
Make oat flour by blending ½ cup of oats in a magic bullet blender. In a separate bowl, combine the oats, oat flour, coconut sugar, baking powder and salt. Add the oil and applesauce then stir to combine.
Spread just over half the crust in the pan and press firmly. Layer with the date mixture. Cover with the remaining crust and press lightly. Bake for about 25-30 minutes or until the crisp golden brown. Let cool on a wire rack for about 4 hours or overnight.