Preheat the oven to 350 F.
Grease and lightly dust with flour a bundt pan. If you are using a silicone bundt pan, don’t worry about adding flour to it, just lightly grease it.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In the bowl of a stand mixer fitted with the paddle or whisk attachment, cream the sugar and butter on high speed for 2 minutes. Scrape the sides and bottom of the bowl.
Beat in the egg whites and whole eggs, and mix on medium speed.
Add in the buttermilk, almond extract, and vanilla extract, mix well.
Add the flour mixture and mix just until incorporated. Scrape the sides and bottom of the bowl.
Transfer the cake batter into the prepared bundt pan.
Bake for 1 hour or until a toothpick inserted in comes out clean or with just a few moist crumbs.
Remove from the oven and place onto a cooling rack to cool.
Once the cake is cool, invert it onto a cake stand or plate.
Make the glaze by combining the ingredients in a small bowl until smooth.
Drizzle the glaze over the top of the cake and sprinkle with some slivered almonds on top.
After the glaze has set, slice and serve the dessert.