Mix flour, both sugars, cinnamon, and salt. Stir in melted butter until crumbly. Set aside.
2. Make the Cake
Preheat oven to 350°F (175°C). Grease and flour a 9-inch springform pan (or 9×9 square pan).
In a bowl, whisk flour, baking powder, baking soda, and salt.
In a large bowl, cream butter and sugar until light and fluffy.
Beat in eggs one at a time, then vanilla.
Mix in sour cream and milk. Gradually add dry ingredients until just combined.
3. Make the Cream Cheese Layer
Beat cream cheese, sugar, egg, and vanilla until smooth.
4. Assemble
Spread half the cake batter into pan.
Spread cream cheese mixture evenly on top.
Scatter blueberries over cream cheese layer.
Spoon remaining cake batter gently on top.
Sprinkle with crumb topping.
5. Bake
Bake 50–60 minutes, until a toothpick comes out clean (avoid poking into cream cheese layer).
Cool completely before slicing.
🌟 Tips
Use lemon zest in the cream cheese layer for brightness.
Tastes amazing warm or chilled.
Freezes beautifully — wrap slices individually for a grab-and-go treat.
Would you like me to also give you a quick coffee cake version (just cake + crumb topping + blueberries, skipping the cream cheese layer) for busy mornings?
