Prepare the Blackberry Filling:In a medium saucepan, combine 1 cup blackberries, ⅛ cup sugar, and 1 tbsp lemon juice. Cook over medium heat until the blackberries are soft and juicy, about 5-7 minutes. Stir occasionally to prevent sticking. In a small bowl, mix 2 tsp cornstarch with 1 tbsp water until smooth, then stir this mixture into the saucepan. Cook for an additional 2-3 minutes until the filling thickens. Remove from heat and allow to cool completely.

Make the Cream Cheese Filling:In a mixing bowl, beat 8 oz cream cheese and ¼ cup sugar together until smooth and creamy. This can be done using a hand mixer or a whisk. Set aside.

Assemble the Wontons:Take a wonton wrapper and place it on a clean, flat surface. Add a spoonful of the cooled blackberry filling and a spoonful of the cream cheese filling in the center of the wrapper. Moisten the edges of the wrapper with your fingers dipped in water. Fold the wrapper over the filling to create a triangle, pressing the edges to seal tightly. For a decorative touch, you can pinch the edges to create a fun pattern. Repeat this process until all the fillings are used.

Fry the Wontons:In a large skillet, heat 1 cup vegetable oil over medium heat. Once the oil is hot (a drop of water should sizzle when it hits the oil), carefully add a few wontons at a time, being careful not to overcrowd the pan. Fry for about 4-5 minutes, flipping occasionally, until the wontons are golden brown and crispy. Use a slotted spoon to remove the wontons and transfer them to a plate lined with paper towels to drain the excess oil.

Dust with Powdered Sugar:While the wontons are still warm, dust them lightly with optional powdered sugar for a sweet finish before serving.