In a medium bowl, mix together the dry ingredients: flour, baking soda, salt, and the slivered almonds.
In a separate bowl, mash together the bananas, sugar, vegetable oil, eggs, and almond flavoring. Combine the two bowls together and fold until combined.
Pour into regular-sized muffin tins until about 2/3 of the way full. Bake at 350 degrees Fahrenheit for 22-25 minutes, or until golden brown and completely baked.
To make the glaze, whisk together the Amaretto and powdered sugar until smooth and shiny. Drizzle over the cooled muffins, and sprinkle with slivered almonds, if desired.