Preheat oven to 375 degrees.
Cut each biscuit into fourths (in the end you should have about 40 triangles).
Spray a large 13×9" baking dish with cooking spray.
In a small bowl, stir together brown sugar and cinnamon.
Dip each biscuit piece, a few at a time, in melted butter.
Roll in cinnamon-sugar and place into prepared baking dish in a single layer.
Sprinkle half of the oatmeal on top of the biscuits.
In another small bowl, stir together blueberries, lemon zest and sugar.
Sprinkle blueberry mixture on top of oatmeal-biscuit mixture.
Top with remaining oats.
Bake for 20 minutes until bubbly and biscuits are golden brown.
Let rest for a few minutes before serving.
