01 - Combine ricotta, sugar, lemon zest, lemon juice, vanilla, and salt in a mixing bowl. Beat until completely smooth and creamy, ensuring no lumps remain.
02 - In a separate chilled bowl, whip heavy cream with an electric mixer until stiff peaks form. Gently fold the whipped cream into the ricotta mixture until fully incorporated and uniform.
03 - Transfer the lemon cream filling to a piping bag fitted with a large tip. Pipe the filling evenly into both ends of each cannoli shell, filling completely but not overstuffing.
04 - Beat egg whites and cream of tartar with an electric mixer on medium speed until soft peaks form. Gradually increase speed to high and add sugar one tablespoon at a time, beating until stiff, glossy peaks form. Fold in vanilla extract.
05 - Spoon or pipe the meringue onto the filled ends of each cannoli, creating decorative peaks and swirls.
06 - Using a kitchen torch, lightly toast the meringue until golden brown, moving the torch constantly to prevent burning. Alternatively, place cannoli on a baking sheet and broil for 1-2 minutes, watching closely.
07 - Arrange cannoli on a serving platter and serve immediately while shells remain crisp and meringue is lightly toasted.