Have ingredients at room temperature. Position rack in lower third of oven; preheat to 325°F. Generously grease and flour a 6-well bundtlette pan.

To make cakes, over a sheet of waxed paper, sift together flour, baking powder and salt. In the bowl of an electric mixer fitted with the flat beater, beat almond paste on low speed until small crumbs form, about 1 min. Gradually add sugar while beating; beat in butter 1 Tbs. at a time. Increase speed to medium; beat until fluffy, about 3 min. Gradually add eggs, beating well after each addition. Beat in orange oil. Reduce speed to low; add flour mixture.

Spoon batter into prepared pan; spread evenly. Bake until a toothpick inserted into cakes comes out clean, about 25 min. Transfer to a wire rack; cool 10 min. Tap pan on work surface, set rack over waxed paper and invert cakes onto rack.

To make glaze, in a small saucepan over medium-low heat, combine rum, water, sugar and butter; heat until butter melts, about 1 1/2 min. Bring to a boil; cook, stirring occasionally, for 30 sec. Cool 1 min.; stir in orange oil.

Brush warm cakes with glaze. Let cool completely. Dust lightly with confectioners' sugar.