Preheat oven to 350 degrees F. Grease a 9 x 13-inch baking pan.: The kitchen fills with a warm, toasty scent as the oven warms, signaling readiness. Greasing the pan ensures the crust releases cleanly after baking, so you will get neat slices. One reason this matters is that a sticky crust can tear when you lift it out, so thorough greasing is a simple insurance policy. A common slip is not preheating fully, which leads to uneven browning; wait until the oven reaches temperature before putting the pan in.
Make the Crust: In a medium bowl, whisk together the flour and ground walnuts. Using a pastry blender or two knives, cut the butter into the flour mixture until it is crumbly and no pieces of butter remain larger than a pea. Turn the mixture into the prepared pan and press into an even layer. Bake until lightly brown around the edges, about 15 minutes. Remove from the oven and allow to cool completely.: In a medium bowl, whisk together the flour and ground walnuts. : The dry mixture should smell faintly nutty, and whisking distributes the finer ground walnuts evenly so each bite tastes consistent. Proper blending avoids pockets of nut or flour which could bake unevenly. If you skip thorough whisking, you may notice uneven texture after baking, so take a moment here.
Make the Cheesecake: Using an electric mixer on medium speed, beat the cream cheese, powdered sugar and milk until smooth and light, 2 to 3 minutes. Spread in an even layer over the cooled crust.: As you cut in the butter , the mixture should transform into a coarse sand like texture, with tiny flecks of butter visible. This is the stage that creates a tender crust, because those small butter bits create pockets that bake into flakiness. Work quickly to keep the butter cool, as melted butter will make the mixture greasy and the crust dense. Avoid overworking the mixture which can cause toughness.
Sprinkle the chopped walnuts over the cream cheese layer, then spread the Cool Whip in an even layer on top of the walnuts. Spoon the cherry pie filling on top of the Cool Whip. Cover with plastic wrap and refrigerate overnight before serving. Leftovers should be stored, covered, in the refrigerator, for up to 4 days.: Pressing should feel firm and steady under your palm, creating an even, compact base that will hold the filling. Use the back of a measuring cup for an even surface if you like. A good visual cue is a uniform surface without loose crumbs; if it looks uneven the cheesecake may tilt when sliced. Do not press so hard that the crust becomes rock hard, as that will be unpleasant to cut through.
Bake until lightly brown around the edges, about 15 minutes.: During baking you will notice a toasty aroma as the fats brown and the ground walnuts toast. Light golden edges are the sign the crust is done; if it is too pale the base may be underbaked and crumbly, and too dark will taste bitter. Oven temperatures vary, so check visually rather than relying only on time.
Remove from the oven and allow to cool completely.: Cooling lets the crust firm up so the filling does not sink or melt into it, and it takes the edge off heat that would otherwise soften the cream cheese . The room will cool and the crust will stop releasing steam, which helps the layers remain distinct. Placing warm filling on a hot crust is a common mistake that causes separation, so be patient.
Make the Cheesecake: Using an electric mixer on medium speed, beat the cream cheese, powdered sugar and milk until smooth and light, 2 to 3 minutes. : As you blend, the mixture will transform from dense and slightly lumpy to glossy, smooth, and aerated; that airy texture is key to a pleasant mouthfeel. The sound of the mixer will change as the lumps disappear into a silky hum. If the mixture looks lumpy, stop and scrape the bowl, then continue at medium speed. Over mixing at high speed can warm the cream cheese and make the filling too soft.
Spread in an even layer over the cooled crust.: Spreading should feel effortless, the filling gliding over the crust like a spreadable cloud. A warm offset spatula helps achieve a flat surface and prevents tearing the base. Visual cues include a smooth top with no gaps between crust and filling; if the filling pools, it may have been over loosened, so keep the texture slightly firm.
Sprinkle the chopped walnuts over the cream cheese layer, then spread the Cool Whip in an even layer on top of the walnuts.: The chopped walnuts provide audible crunch and visual interest; you will hear a faint crackle as your knife slices through them. Spreading the Cool Whip creates a soft, pillowy contrast that helps balance the denser filling below. Work gently so you keep the crunchy texture intact; overworking will pulverize the pieces and lose contrast.
Spoon the cherry pie filling on top of the Cool Whip.: The glossy cherry pie filling should sit like a jewel on top, its syrup pooling slightly at the edges. The brightness of the cherries lifts the dessert both visually and in flavor. If you spoon too heavily in one spot, the topping can slump, so distribute evenly for pretty slices.
Cover with plastic wrap and refrigerate overnight before serving.: Chilling overnight allows the filling to set and flavors to meld, and you will notice the whole cake firming to perfect slice able texture. Refrigeration also helps the crust re unify and makes cutting neater. A common oversight is serving too soon; insufficient chilling leads to sloppy slices and a weepy topping.
Leftovers should be stored, covered, in the refrigerator, for up to 4 days.: Stored slices keep well and the layers remain distinct, though the Cool Whip may soften over time and the crust may hydrate slightly. Keep it covered to prevent refrigerator odors from seeping in, and serve chilled for best texture. Freezing is possible but can change texture, so prefer refrigeration for short term storage.
