In a bowl, using an elecric mixer on medium speed, beat the butter with dark brown sugar, white sugar and vanilla for about 3 minutes.
Add in eggs and beat until well blended.
In a bowl mix together the flour with baking powder, baking soda and salt.
Add to the creamed mixture alternating with the half and half cream or full-fat milk.
Transfer the batter to prepared tube pan.
Bake for about 1 hour and 30 minutes or until cake tests done.
Cool in pan for 10 minutes; remove from pan; cool completey on wire rack.
To make the glaze; in a heavy saucepan cook both sugars with whipping cream and butter over medium heat, stirring constantly until the butter melts and the sugars have dissolved.
Increase the heat and bring to a boil; cook stirring constantly for about 3 minutes or until slightly thickened; stir in vanilla.