Preheat your oven to 325° for a glass plate or to 350° for a metal plate.
Apply a light coating of butter to the insides of the pie plate, then add 1 or 2 tablespoons of sugar. Gently turn the plate allowing the sugar to stick to the butter coating both the bottom and sides of the plate. Discard any excess sugar.
Mix the eggs, sugar, flour, and almond extract in a medium-sized bowl by hand. Then, slowly add the melted butter while beating to temper the eggs so they don't get cooked.
Pour the batter into the prepared pie plate and place into the oven and bake for 15 to 20 minutes until the cake is a light golden brown. Remove the pie from the oven and allow to cool.
While the cake is baking, mix the frosting by combining the ingredients in a medium-sized bowl. A hand mixer works well for this.
Spread the frosting evenly onto the warm cake then sprinkle with the sliced almonds.
Serve warm or at room temperature.