1. Bring half-and-half, 3 Tbsp sugar, and salt to simmer in medium saucepan over medium heat, stirring occasionally. Whisk egg yolks, cornstarch, and remaining sugar in medium bowl until smooth. Slowly whisk 1 cup warm half-and-half mixture into yolk mixture to temper, then slowly whisk tempered yolk mixture into remaining half-and-half mixture in saucepan.

2. Cook half-and-half mixture over medium heat, whisking constantly, until mixture is thickened and registers 180 degrees, about 30 seconds. Off heat, whisk in butter, semisweet chocolate, unsweetened chocolate, and vanilla until smooth. Strain pudding through fine-mesh strainer into clean bowl. Spray piece of parchment paper with vegetable oil spray and press directly against surface of pudding. Refrigerate until chilled, at least 1 hour or up to 3 days.

3. Just before serving, add 1 Tbsp cookie crumbs to each of twelve 4-oz wide-mouth Mason jars, followed by approximately 1/2 cup pudding. Top with whipped cream and sprinkle with remaining cookie crumbs.