Preheat your oven to 350°F (175°C) and grease your 9x13 inch baking pan or line it with parchment paper for easy removal.
In a large mixing bowl, combine the softened butter, granulated sugar, and brown sugar. Beat them together until the mixture is light and fluffy, which should take about 2-3 minutes.
Stir in the beaten egg yolk and vanilla extract, mixing until well combined.
In a separate bowl, whisk together the cake flour and cornstarch. Gradually add this dry mixture into the wet ingredients, stirring until just combined.
Gently fold in the milk chocolate chips and coarsely chopped almonds into the cookie dough until evenly distributed.
Pour the cookie dough into the prepared baking pan, using a spatula to spread it evenly across the bottom.
Bake in the preheated oven for 20-25 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out clean.
Allow the cookie bars to cool in the pan for about 10 minutes before transferring them to a wire rack to cool completely. Once cooled, cut them into squares and serve.
