For an even crispier shell, bake the roll-ups on the upper third rack and allow them to cool completely before transferring from the pan. If you prefer a stronger blueberry flavor, stir an extra tablespoon of blueberries into the filling and reduce the amount of sweetener slightly to keep carbs in check. You can customize the flavor by adding a pinch of nutmeg, more lemon zest, or a drop of almond extract to the filling. Avoid overfilling the rolls, since too much filling can cause cracks and leaks that soften the crust. To keep this recipe strictly keto, stick to the listed portion size because blueberries, while allowed, can increase carbs quickly if you go overboard.