preheat oven to 425F
cream together 1/2 cup softened butter + 1/2 cup granulated sugar + 1 tsp vanilla
microwave 1/2 cup milk of choice for 20 seconds and mix in
whisk in 1 egg just until combined
add in 1 1/2 cup all purpose flour + 1 tsp baking powder and stir all together
scoop evenly in a lined & oil muffin pan (6 big muffins)
streusel: mix together 4 tbsp melted butter + 1/2 cup brown sugar + 1/2 cup all purpose flour + 2 tsp cinnamon
add evenly on top of muffins
bake for 5 min, lower temp to 350F and bake for another 16-18 min or until golden and toothpick comes out clean