Vanilla Custard Cream Squares 🍰

Ingredients:
For the crust:

1 ½ cups graham cracker crumbs
⅓ cup melted butter
¼ cup granulated sugar
For the custard:

2 cups whole milk
1 cup heavy cream
¾ cup granulated sugar
5 large egg yolks
2 tsp vanilla extract
3 tbsp cornstarch
For the whipped cream: