Preheat the oven to 350°F (175°C). Grease a 9-inch round cake pan and set it aside.
In a large bowl, whisk together the melted unsalted butter, granulated sugar, and vegetable oil until smooth.
Add the vanilla extract, almond extract, and the room-temperature eggs to the butter mixture and whisk until fully combined.
In a separate bowl, whisk together the all-purpose flour, almond flour, baking powder, and kosher salt until evenly distributed.
Fold the dry ingredients into the wet ingredients with a rubber spatula, mixing just until no streaks of flour remain.
Transfer the batter to the prepared cake pan and smooth the top. Sprinkle the ⅓ cup sliced almonds evenly over the batter.
Bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean. Start checking at 25 minutes.
Cool the cake in the pan for 10 minutes, then transfer to a cooling rack to cool completely.
Top the cooled cake with additional sliced almonds and dust with powdered sugar if desired before serving.