Grease a 12-cup muffin pan with nonstick spray or line with paper liners.
In a medium bowl, whisk together the flour, sugar, baking powder, and salt. Set aside.
In a separate large bowl, whisk together the milk, eggs, melted butter, and vanilla extract until combined.
Mix the flour mixture into the bowl with the wet ingredients until just combined.
Gently fold in the raspberries and white chocolate chips until combined.
Divide the batter evenly among the muffin cups, filling each one about ¾ full. Set aside.
In a small bowl use a pastry blender, a fork, or your fingers to combine the streusel ingredients until the mixture is crumbly.
Sprinkle the streusel over the muffin batter.
Bake in the preheated oven for 18 to 20 minutes until the muffins are golden brown and a toothpick inserted in the center comes out clean. Let cool completely.
If making the glaze, in a small bowl whisk together the powdered sugar and milk until smooth (the glaze should be thick, but still easy to drizzle).
Use a spoon to drizzle the glaze over the tops of the muffins.