Preheat oven to 325 degrees. Generously spray mini Bundt cake
pans with cooking spray. Sift together the flour,
baking powder, and salt in a medium bowl. Combine
buttermilk and rum in a glass measure.
Cream butter and both sugars in a mixer bowl on
high speed until light and fluffy, about 3 minutes. Add
eggs one at a time, beating well between each; mix
on medium speed until combined. Add flour and
buttermilk mixtures, alternating between them, and
beginning and ending with flour.
Fill each cake pan with about 1/2 cup batter; tap pan
against the counter to remove any air bubbles and to
evenly distribute batter. Bake until tops spring back
when touched lightly, edges begin to pull away from
pan, and a cake tester inserted in the centers comes
out clean, 18 to 20 minutes. Transfer pan to a wire
rack for 15 minutes; then invert pan to unmold cakes onto rack. Let cool completely.
To serve, whisk together glaze ingredients until
smooth, and drizzle 1 1/2 tablespoons over each cake.
Cakes may be stored at room temperature, wrapped airtight in plastic wrap, up to 3 days.
These look interesting might have to try making it and let you all know how it turned out.