Place rack in the center of the oven and preheat to 350 degrees F. Butter and flour one cake or small cake pans or ramekins.
In a medium bowl, whisk together flour, baking powder and salt. Set aside.
Place the butter and the sweet condensed milk in a bowl. Beat on medium speed until fluffy and pale brown, about 3 minutes.
Stop the mixer, scrape down the sides of the bowl and add one egg. Beat on medium for one minute. Add the remaining eggs, one at a time, beating for one minute between each addition. Stop the bowl and scrape down the sides as necessary. Beat in vanilla extract.
Add half of the flour mixture to the egg and butter mixture.Beat on low speed until just incorporated.
Stop the mixer, scrape down the bowl and add the rest of the dry ingredients. Beat on low speed until just incorporated.
Divide the batter between the prepared cake pans, filling each about two thirds full. Bake for about 25 to 30 minutes or until a toothpick inserted in the center of one of the cakes comes out clean.
Let the cakes rest in the pans before removing to a wire rack to cool completely.
To make the glaze: in a medium bowl, mix all the ingredients until smooth. Drizzle on top the cooled cakes.