Preheat oven to 425 degrees F.
For the topping: combine first four ingredients with a fork. Set aside.
For the muffin batter: In a medium bowl whisk together the flour, sugar, baking powder and salt.
In a smaller bowl combine the egg, oil, milk and vanilla.
Make a well in the center of the dry ingredients.
Pour the egg mixture in the well. Stir just until mixed.
Fold in strawberries.
For the cream cheese mixture: In the bowl of a standing mixer combine cream cheese and sugar until fluffy (2 minutes.)
Add the milk and vanilla until mixed well.
Using a large scoop, divide muffin batter into the twelve vessels filled with cupcake liners.
Using a small scoop, add the cream cheese mixture to the batter. Swirl with a knife to combine.
Top each muffin with streusel mixture.
Bake at 425 degrees for 6 minutes. Lower oven temp. to 350 degrees and bake for 20 minutes more or until a knife inserted into center of a muffin comes out clean.