Preheat the oven to 375 degrees F. Line a 12-cavity muffin tin with paper liners or spray with non-stick spray.
To make the muffins: Whisk the flour, 1/2 cup of the sugar, the baking powder, and salt in a large bowl to combine. Whisk the buttermilk, cocoa, food coloring, oil and egg in a separate bowl. Stir the wet ingredients into the dry just until moistened (some lumps should remain).
Beat the cream cheese and remaining 1/4 cup sugar in a small bowl. Fold into the muffin batter, being careful to not over mix (some streaks of the cream cheese mixture should remain). Fill the muffin tins two-thirds full with the batter.
To make the crumb topping: Stir the sugar and flour in a small bowl to combine. Add the butter and cut in to with two knives or a pastry blender until you have coarse crumbs. Sprinkle the crumb topping evenly over the muffins.
Bake until a toothpick inserted comes out clean, 17 to 20 minutes. Cool in the pan for 10 minutes, then remove to a rack to cool completely.