Preheat oven to 375 degrees F. Lightly oil muffin tin.
Mix all dry ingredients into a large bowl. Add frozen cranberries or blueberries, turning in to coat with flour. Adding the berries to the flour mixture helps keep them spread throughout the muffins instead of settling to the bottom.
Whisk the eggs, milk, yogurt, oil, vanilla and lemon juice together.
Pour wet mixture into dry mixture and gently mix just until ingredients are combined. Do not overmix.
Combine streusel ingredients together, cutting cold butter with a fork until mixture is crumbly.
Divide muffin mix into muffin tins. sprinkle tops with streusel topping mix, about 1 tablespoon per muffin or to your desired amount.
Place in the oven and bake for 20 to 25 minutes or until golden brown and toothpick inserted into center comes out clean.
Allow to cool in muffin tin for about 5 minutes before removing to a wire rack to finish cooling.
For best freshness, store in an airtight container in the fridge.