Mix the flour with the softened butter, a pinch of salt, and 1/3 cup of water until you obtain an even dough; wrap it in plastic wrap and let it chill in the fridge for 30 minutes. Blend the walnuts in a food processor together with 1/2 tablespoon of granulated sugar and the almond flour. Beat the egg yolks with 1/4 cup of granulated sugar. In a separate bowl, beat the egg whites with a pinch of salt; when they are a bit fluffy, add a tablespoon of granulated sugar and continue to beat until they form stiff peaks. Add the walnuts to the beaten egg yolks; add in the mascarpone and whisk together. Then add in a packet of vanillina and the cream. Incorporate half of the egg whites into the mixture, then add in the other half, mixing gently and ensuring the egg whites remain fluffy. Roll out the dough until it is 1/8-inch thick and use it to line an 8 1/2-inch round baking pan, letting about 2 inches hang over the edges. Pour in filling, then trim the excess dough into uneven points and fold them over the filling. Dust with powdered sugar and bake at 375°F for 50-55 minutes. Remove the pie from the oven, let it cool, and serve dusted with powdered sugar.