Preheat your oven to 400 F degrees and line 6 cupcake wells in a tin with paper liners.
In a mixing bowl, whisk together flour, sugar, and cinnamon until well combined.
Add in the butter and stir until the mixture becomes crumbly.
In another bowl, beat together the cream cheese, sugar, and vanilla until smooth.
In a separate bowl, whisk together another batch of sugar and an egg.
Add the sour cream to the wet mixture and whisk to combine.
Combine the dry ingredients with the wet mixture.
Gently fold in most of the blueberries to avoid breaking them.
Spoon some of the batter into 6 of the muffin tin wells, filling them about halfway.
Add a dollop of the cream cheese mixture into each well, then top with more batter until almost full.
Finish with a sprinkle of the streusel topping and any reserved blueberries.
Bake for 5 minutes at 400 F, then reduce the temperature to 375 F and bake for an additional 15 minutes.
Allow the muffins to cool on a rack before removing them from the pan.
