Line a 8 inch square pan with parchment paper, leaving enough overhang on top to act as handles so you can lift the bars out of the baking pan later.
Line the bottom of your prepared pan with graham crackers. You want to do your best to cover the bottom of the pan with crackers with no gaps, so you may need to cut some of them to fit. I used about 18 crackers.
Add cream cheese to a large mixing bowl. Beat on high speed with the wire whisk attachment until it is light and creamy, about 1 minute. Scrape down the sides of your mixing bowl a few times as needed to make sure all the cream cheese gets beaten.
Add in the condensed milk. Beat on medium speed until you have a smooth batter. Add in the lemon juice. Mix on low speed until the lemon juice is evenly incorporated. Scoop about 2 tbsp of filling out. Allow the rest of the mixture to thicken for about 5 minutes.
Thinly spread the scooped 2 tbsp of filling across the graham crackers in your baking pan, just covering the surface of them. This will act as a glue for the second layer of graham crackers. Add a second layer of graham crackers on top of the first.
Transfer the filling to your prepared pan. Use an offset spatula to smooth and level the surface. Place into the fridge for about 3 hours or overnight to firm up. Keep bars in the fridge until ready to serve.
When ready to serve, remove the bars from the baking pan. Cut the bars with a large sharp knife, wiping the blade clean between each cut. Use a cookie spatula to lift the bars onto plates. You can also garnish the tops with whipped cream and lemon slices. Store any uneaten bars in an airtight container in the fridge or freezer.
Notes
Graham cracker note: Graham crackers usually come in sheets that can be broken into smaller individual crackers (usually 4 to a sheet). 36 crackers refers to the individual crackers. You can do just a single layer of crackers if you prefer less crust or think your crackers are thick enough. I like doing a double layer for a thicker crust.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.