In a large bowl, stir together flour, salt, baking powder and spices.
With an electric mixer, beat butter and sugar in a separate bowl.
Add molasses and eggs to mixer and beat well.
Beat in milk and vanilla until well combined.
Pour liquid ingredients into dry ingredients, stirring with a spoon to combine.
Spoon some batter into 12 greased muffin cups. You'll use half the batter for this step.
Dollop a teaspoon of marmalade onto each muffin.
Top with remaining batter.
Bake at 400 degrees for 15 minutes or until a toothpick comes out clean.