Combine flour, 1/4 cup plus 1 tablespoon butter, sugar, egg, baking powder, and vanilla extract in a food processor. Blend ingredients until dough starts sticking together and forms one piece.

Wrap crostata dough in plastic wrap and place in the refrigerator for 30 minutes.

Preheat the oven to 350 degrees F (175 degrees C).

Remove dough from the refrigerator. Roll out dough using a lightly floured rolling pin on a work surface, or flatten it directly onto a baking sheet using your fingers, to form crostata shell. Pierce shell with a fork to prevent air bubbles during baking.

Bake in the preheated oven until sides are golden brown, 15 to 20 minutes.

Remove crostata from the oven and set aside to cool.

While crostata cools, pour lemon juice into a heavy saucepan through a sieve and stir in 3 1/2 tablespoons sugar. Heat mixture over medium-low heat until sugar dissolves, about 5 minutes. Remove from heat.

Beat remaining sugar, eggs, and flour together in a mixing bowl using an electric mixer or a whisk until white and airy in texture.

Pour warm lemon juice mixture into egg mixture slowly, whisking constantly. Pour custard mixture back into the saucepan.

Heat custard mixture over medium-high heat, stirring constantly until thick, about 5 minutes. Remove from heat and continue to mix until the uneven texture becomes smooth, about 1 minute. Add butter gradually to custard 1 piece at a time, stirring constantly, until smooth. Let custard cool to room temperature.

While custard cools, combine ricotta cheese, whipping cream, confectioners' sugar, and lemon zest in a food processor. Blend until mixture is uniform and smooth in texture, 2 to 3 minutes. Transfer ricotta cream to a bowl.

Place lemon custard and ricotta cream in the refrigerator to cool completely, about 30 minutes.

Remove custard and cream from the refrigerator. Spread lemon custard evenly on cooled crostata crust. Spread ricotta cream on top of lemon custard. Decorate with raspberries. Keep refrigerated until ready to serve.