Add the butter to the bowl of a stand mixer fitted with a whisk attachment and whip on medium speed for 1 minute. With the mixer running, slowly pour in the maple syrup and 1 teaspoon of the vanilla bean paste and whip until completely combined. Transfer to a serving bowl and reserve.
Keep the rolls intact and slice across the equator to create 1 large top and 1 large bottom roll. Place the bottom roll in the baking dish, then spread with 2 tablespoons of the maple butter. Sprinkle with the lemon zest and half of the blueberries and top with the top roll.
In a medium bowl, whisk together the milk, cream, sugar, eggs, remaining 1 teaspoon vanilla bean paste and a pinch of salt. Pour the mixture over the rolls. Cover and refrigerate at least 8 hours.
Preheat the oven to 400 degrees F.
Cover the baking dish with foil and bake for 40 to 45 minutes. Remove the foil, then continue to bake until golden brown, about 10 more minutes.
Arrange scoops of the maple butter on top and sprinkle with the bacon and remaining blueberries. Serve with additional maple syrup.