In a small saucepan, combine all ingredients for the strawberry preserve. Cook over medium heat for about 8 minutes until the berries cook down and soften, and the mixture thickens. Make sure to stir occasionally while it cooks. Transfer to a heat proof bowl and let cool completely.
Preheat oven to 350 degrees F. and line a cupcake pan.
In a large bowl, combine flour, baking powder, and salt. Set aside.
In a medium bowl, whisk together yogurt, oil, sugar, eggs, vanilla and milk. Add to the flour mixture, and stir until a smooth batter forms. Fold in white chocolate chips. Set aside and prepare your streusel.
For the streusel, mix together flour, oats, sugar, vanilla powder and butter with a fork or with your hands, until a crumbly mixture forms.
Place 1 tablespoons of muffin batter at the bottom of each cupcake liner. Then, with a teaspoon add strawberry preserves. Top with another tablespoons of batter.
Sprinkle the streusel liberally over each muffin, and sprinkle with a little bit of sugar.
Bake for about 20 minutes or until the edges are slightly golden and the cake tester comes out clean.
