In a large bowl, cream together butter and sugar until light and fluffy. Beat in egg and vanilla, then stir in milk.
4 tablespoons butter, 3/4 cup granulated sugar, 1 large egg, 1 teaspoon pure vanilla extract, 3/4 cup milk
Stir dry ingredients into butter mixture; mix until well-incorporated. Pour batter into prepared pan.
Using a teaspoon, dollop cranberry sauce on top of batter. With a knife, drag sauce through batter to create marbled pattern.
1/2 cup cranberry sauce
To make the topping, in a small bowl, mix together flour, brown sugar, melted butter, and pecans until mixture is crumbly. Scatter across the top of the batter.
1/4 cup all-purpose flour, 1/4 cup brown sugar, 2 tablespoons butter, 1/2 cup chopped pecans
Bake coffee cake for 35-40 minutes, until a toothpick inserted in the center comes out clean.