Preparation Steps

• Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.
• In a large bowl, cream together butter, granulated sugar, and brown sugar until light and fluffy. Beat in egg and vanilla extract.
• In a separate bowl, whisk together flour, baking soda, and salt. Gradually add to the wet ingredients, mixing until just combined. Stir in chocolate chips.
• Drop by rounded tablespoons onto the prepared baking sheet. Bake for 10-12 minutes, or until golden brown. Let cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.
• Prepare the pastry cream: In a saucepan, whisk together milk, sugar, cornstarch, and egg yolks. Cook over medium heat, stirring constantly, until the mixture thickens and comes to a simmer. Remove from heat and stir in vanilla extract. Let cool completely, pressing plastic wrap directly onto the surface to prevent a skin from forming.
• Prepare the chocolate ganache: Place chocolate chips in a heatproof bowl. Heat heavy cream in a saucepan until simmering. Pour over chocolate chips and let sit for a minute. Stir until smooth.
• To assemble the cookie bites, spread a small amount of pastry cream on the bottom of one cookie. Top with another cookie. Drizzle with chocolate ganache.