Step 1: Preheat and Prepare the Pan
Preheat your oven to 350°F (175°C). Line a 9×9 inch baking pan with parchment paper to ensure easy removal of the squares later on.
Step 2: Make the Crust
In a mixing bowl, combine the graham cracker crumbs, melted butter, and 1/4 cup of granulated sugar. Mix until the crumbs are evenly coated and mixture resembles wet sand. Press this mixture firmly into the bottom of the prepared pan. Bake for 10 minutes until set and lightly golden. Remove from the oven and let it cool completely on a wire rack.
Step 3: Create the Custard Mixture
In a medium saucepan, heat the whole milk and heavy cream over medium heat until it reaches a gentle simmer. While the milk mixture is heating, whisk together 1 cup of granulated sugar and 1/2 cup of flour in a separate bowl. Add the 4 egg yolks to the dry ingredients and mix until smooth and creamy.
Step 4: Temper the Egg Mixture
Once the milk is simmering, carefully pour it over the egg yolk mixture while whisking constantly. This step is crucial as it gradually raises the temperature of the eggs without scrambling them.
Step 5: Cook the Custard
