In a large bowl, mix together the flour, sugar, baking powder, and salt.
Add in the milk, eggs (one at a time) and vanilla.
Slowly pour in melted butter and mix well.
Prepare a well-greased 9x13 pan. Pour the cake batter into the pan.
Prepare the topping:
Mix topping ingredients (butter, dark brown sugar, flour, raisins, cinnamon and cardamom) together with a large spoon, and spoon onto the cake mixture.
Take a knife or fork and swirl the topping into the cake mixture, trying to stay on the top part of the cake, from side to side.
Bake at 350 for 30-35 minutes. Remove from the oven and allow to cool for 10 minutes.
Make the glaze:
Whisk ingredients together to make the glaze (powdered sugar, butter, vanilla, maple extract, milk).