1-First Step: Set up the pan. Line an 8×8-inch square baking pan with parchment paper, leaving a little overhang on the sides so you can lift the slab out later. Coat the paper lightly with cooking spray. This small step makes the finished Boston Cream Pie Bars much easier to remove and slice.

2-Second Step: Make the cookie crust. Place the vanilla wafer cookies and granulated sugar in a food processor. Pulse until fine crumbs form. If you do not have a processor, place the cookies in a sealed plastic bag and crush them with a rolling pin until they are very fine. Pour the crumbs into a bowl, then add the melted unsalted butter. Stir until the mixture looks like damp sand. Press the crumb mixture firmly into the bottom of the prepared pan. A flat-bottomed measuring cup works well for an even layer. Freeze the crust for 15 minutes so it sets before the filling goes on top.

3-Third Step: Mix the vanilla filling. In a medium bowl, whisk the vanilla instant pudding mix with 2 1/2 cups cold heavy cream until smooth and thick. The mixture should look creamy with no dry pockets of pudding mix. If you are making these for a crowd, this filling can be mixed a little ahead of time, but it should be spread soon after whisking so it stays smooth. Take the crust out of the freezer and spread the pudding mixture evenly over the top. Use an offset spatula or the back of a spoon to smooth the surface. Then refrigerate the pan for at least 10 minutes. This short chill helps the layer stay neat when the chocolate ganache is added.

4-Fourth Step: Make the chocolate ganache. Place the chopped semi-sweet chocolate in a heatproof bowl. In a small saucepan, heat 2/3 cup cold heavy cream until it reaches a gentle simmer. Do not let it boil hard. Pour the hot cream over the chocolate and let it sit for a moment so the chocolate softens. Whisk until the mixture becomes glossy and smooth. Let the ganache cool for 3 to 5 minutes before pouring it over the custard layer. Cooling it for about 3 minutes gives a smooth finish, while 5 minutes can help create a more swooping top if you want a decorative look.

5-Fifth Step: Add the chocolate layer. Pour the ganache over the chilled pudding layer and spread it gently with a spatula. Try to move quickly but carefully so the filling underneath stays in place. The chocolate layer should cover the bars from edge to edge, giving these no bake Boston Cream Pie Bars their classic bakery-style finish. If you want a neat top, tilt the pan slightly and let the ganache flow to the corners. If you like a more rustic look, use the back of a spoon to create soft waves in the chocolate before chilling.

6-Sixth Step: Chill until firm. Refrigerate the pan for at least 2 hours so the bars firm up enough to cut cleanly. If you have extra time, a longer chill makes slicing even easier. This is one reason these Boston Cream Pie Bars recipe steps work well for busy schedules: most of the time is hands-off.

7-Final Step: Slice and serve. Lift the slab out of the pan using the parchment paper. Place it on a cutting board and cut into 12 or 16 pieces, depending on how large you want each serving. Wipe the knife clean between cuts for the neatest edges. Serve the bars cold for the best texture. If you are making them for a party, cut them just before serving so they look polished and fresh. These dessert bars work well on a platter with fresh berries, a dusting of cocoa, or simple extra chocolate drizzle.