1. Preheat your oven to 400°F to crisp up the bacon. Lay the bacon strips on a baking sheet lined with parchment paper and bake for 15-20 minutes until crispy.
2. While the bacon is baking, combine the blackberries, sugar, and lemon juice in a small saucepan over medium heat. Stir occasionally until the mixture thickens, about 10 minutes.
3. In a medium bowl, mix the cream cheese with vanilla extract until smooth. Set aside.
4. Season the ground beef with salt and pepper, then form into four patties. Cook the patties on a preheated grill or skillet over medium heat for about 5 minutes per side, or until they reach your desired doneness.
5. Toast the hamburger buns lightly in a pan with a bit of butter for extra flavor.
6. Assemble the burgers by spreading a generous layer of cream cheese on the bottom bun, followed by the burger patty, crispy bacon, and a spoonful of blackberry sauce. Top with the other half of the bun.

Remember, cooking is about experimenting and having fun. Feel free to adjust the thickness of your patties or the sweetness of your blackberry sauce!