With the rack in the middle position, preheat the oven to 350°F (180°C). Butter a 6-cup (1.5 litre), 10 x 4-inch (25 x 10 cm) loaf pan and line with a sheet of parchment paper, letting it hang over both sides.
In a bowl, combine the ground almonds, cornstarch and baking powder.
In another bowl, cream the butter and sugar with an electric mixer. Add the eggs, one at a time, and beat until smooth. On low speed, stir in the dry ingredients alternately with the mashed bananas. Spread the batter into the prepared pan. Sprinkle with the sliced almonds.
Bake for 55 minutes or until the loaf is golden brown and a toothpick inserted in the centre comes out moist but without lumps of batter.
Let cool completely before removing from the pan.
To make gift-sized loaves, bake the batter in four small 6 x 3-inch (15 x 7.5 cm) loaf pans. Sprinkle each loaf with 1 tbsp of sliced almonds and bake for 30 minutes.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.