Preheat oven to 375°F. Line the 12-muffin pan with paper cups.
Prepare the streusel topping. Add all the streusel ingredients in a small bowl. Use a pastry blender or fork to mix, just until a crumbly texture. Set aside.
Sift all the dry ingredients in a medium-sized bowl.
In a separate bowl add softened cream cheese. Heat the milk in a microwave for 30 seconds then add to cream cheese. Mix until the cream cheese is smooth. Stir in melted butter, sugar and eggs. Add vanilla, lemon zest, and lemon juice. Mix until well blended.
Add the dry ingredients to the wet batter and gently fold in just until combined. (Do not over mix)
In a small bowl, toss the blueberries in the flour. Gently fold into the batter.
Scoop and portion the batter into the prepared muffin pan. Sprinkle the streusel mixture overtop.
Bake in preheated oven to 375°F for about 25 to 30 minutes, or until the inserted tester comes out clean.
Let it cool in a muffin pan for 10 minutes, then cool completely on a cooling rack.