Preheat the oven to 350 degrees F. Grease 2 9x5 inch loaf pans.
In a large bowl, cream the butter and sugar until light and fluffy, about 5 minutes. With the mixer on low speed, add the eggs 1 at a time. Add in the vanilla, sour cream, and milk and beat until combined.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt. Add the flour mixture to the wet ingredients, mixing just until flour is combined. Fold in the blueberries with a spatula. Pour batter into the two prepared pans.
Make the topping: In a small bowl, stir together the sugar, flour, and salt. Cut in the butter until crumbly. Sprinkled evenly on top of the batter in the pans.
Place pans in the preheated oven and bake for 45-60 minutes, until top is browned and a toothpick inserted in the center comes out clean. Remove from oven and cool before slicing.
Notes
Source: Adapted from Ina Garten.
Recipe by Wright Family Table at https://www.wrightfamilytable.com/blueberry-muffin-bread/