Preparation of Tortilla Shells: Preheat your oven to 400°F (200°C). In a small bowl, combine the graham cracker crumbs and ground cinnamon, mixing thoroughly. Set this mixture aside. Using a cookie cutter, cut out 4-5 rounds from each tortilla, yielding approximately 24-30 rounds. Dip each tortilla round into the melted butter, ensuring it is fully coated, and then dredge each round in the graham cracker crumb mixture. To shape the tortillas into taco shells, flip a muffin tin upside down and place the prepared tortilla rounds between the inverted cups. Bake in the preheated oven for approximately 10 minutes, or until the shells are golden brown and crisp. Allow the shells to cool on the muffin tin.
Preparation of Homemade Blueberry Sauce: In a small bowl, whisk together the warm water, lemon juice (if using), and cornstarch until fully combined. In a small saucepan set over medium-low heat, combine the blueberries and granulated sugar. Cook the mixture for approximately 4-5 minutes, allowing the blueberries to break down and release their juices. Gradually stir in the cornstarch mixture, then gently simmer the sauce for an additional 3 minutes, or until it has thickened. Remove the saucepan from the heat and allow the sauce to cool to room temperature before use.
Preparation of Cheesecake Filling: In a mixing bowl, combine the softened cream cheese, heavy cream, powdered sugar, lemon zest, and vanilla extract. Using a hand mixer or stand mixer, beat the mixture on medium speed for approximately 2 minutes, or until the filling has thickened and is smooth. Once fully mixed, transfer the filling to the refrigerator to chill for about 30 minutes. This chilling process will make the filling easier to pipe into the taco shells.
Assembly of Blueberry Cheesecake Tacos: Once the tortilla shells have cooled and the cheesecake filling has chilled, transfer the filling to a piping bag. Carefully pipe the cheesecake filling into each tortilla shell, ensuring each shell is evenly filled. Top each filled shell with approximately 1/2 teaspoon of the homemade blueberry sauce or canned blueberry pie filling. For an additional garnish, sprinkle a small amount of graham cracker crumbs over the top, if desired. The Blueberry Cheesecake Tacos are now ready to be served and enjoyed.