Line an 8x8-inch baking dish with parchment paper, leaving overhang on two sides for easy removal later. Mix graham cracker crumbs, melted butter, and 3 tablespoons granulated sugar in a bowl until it resembles wet sand. Press this mixture firmly into the bottom of your prepared dish, using the bottom of a measuring cup to get it even and compact.

Beat softened cream cheese on medium speed for about 2 minutes until it's smooth and creamy with no lumps. Add 1/2 cup powdered sugar and 2 tablespoons lemon juice, mixing until combined. The lemon juice adds brightness to your blueberry cheesecake bars no bake and keeps them from tasting too heavy.

In a separate cold bowl, whip the 1 cup cold whipping cream with 1 tablespoon powdered sugar and 1 teaspoon vanilla powder until stiff peaks form. This takes about 3 minutes with an electric mixer on high speed. Don't skip the vanilla powder—it adds depth that plain whipped cream misses.

Gently fold the whipped cream into the cream cheese mixture using a spatula in 3 additions, being careful not to deflate all those air bubbles. Fold slowly until you don't see white streaks anymore, then stop—overmixing collapses the fluffy texture. Spread this mixture evenly over your crust layer.

Scatter fresh blueberries across the top of the cream cheese layer, pressing them down gently so they stick in place. I use about 1 cup total and try to cover as much surface as possible for that gorgeous presentation. Sprinkle the chopped pistachios over top for crunch and color contrast.

Cover the dish loosely with plastic wrap and refrigerate for at least 4 hours until the filling is completely set and firm to the touch. Overnight is even better if you're making these for entertaining—it gives all the flavors time to meld together beautifully.

Use the parchment paper overhang to lift the whole thing out of the dish and onto a cutting board. Cut into 12 bars with a sharp knife, wiping the blade clean between cuts for neat edges. Store covered in the refrigerator for up to 3 days.