Crush the graham crackers into fine crumbs using a zip-top bag and rolling pin until you have about 1 cup of crumbs. Transfer to a mixing bowl.
Melt the butter in a small saucepan over low heat until fragrant and golden, about 2 minutes. Pour the melted butter over the graham crumbs and stir until evenly coated and crumbly.
Press the crumb mixture firmly into the bottom of your prepared pan, creating an even crust. Chill in the refrigerator for 10 minutes to set.
In a mixing bowl, beat the softened cream cheese with sugar using a spatula or hand mixer until smooth and fluffy, about 2 minutes.
Add the lemon juice and vanilla extract to the cream cheese mixture and mix well until combined.
In a chilled bowl, whip the heavy cream with a mixer until soft peaks form, about 2-3 minutes.
Gently fold the whipped cream into the cream cheese mixture until fully incorporated and smooth, taking care not to deflate the whipped cream.
Spread the creamy filling evenly over the chilled crust using a spatula, smoothing the surface for a neat finish.
Refrigerate the assembled bars for at least 4 hours or overnight until set and firm.
Once set, slice into squares, serve chilled, and enjoy the silky, tangy goodness of these no-bake cheesecake bars.