Preheat oven to 350°F. Grease 8 ramekins (5 oz each) and place a baking sheet.
In the bowl of an electric mixer, beat butter with brown sugar until light and fluffy; add eggs and mix until well combined.
In a medium bowl, whisk together the flour and baking powder.
Add flour mixture to batter in 3 additions, alternating with the milk and mix just until combined. Spoon into prepared ramekins, dividing evenly, and spread the tops of each dish until smooth.
Meanwhile, make sauce. In a medium saucepan over high heat, boil milk until very hot and then add butter to stir. Add remaining sauce ingredients and cook until mixture comes to a boil, then reduce heat to medium and boil for 2 minutes. Carefully pour sauce mixture (again, dividing evenly) over batter in pan. Do not stir.
Bake in preheated oven for 15-20 minutes, or until cake is set (pulling away from sides of ramekins) and a test pick comes out clean.
Serve warm with a drizzle of cream or a scoop of ice cream.