How to Make It
Yield: 19.5 ounces (560 grams); enough for two 10-inch tart shells. Place the butter, salt, sugar, egg and almond flour in a medium-size mixing bowl. Use an electric mixer set on medium speed to beat the mixture just until combined. Add the cake flour and mix just until the dough is smooth and holds together, about 30 seconds. Remove the dough from the bowl and pat into a disk. Wrap the dough in plastic wrap and place in the refrigerator for at least one hour before using. This will give any gluten that may have developed a chance to relax. If you use the dough immediately after making it, it may be tough and elastic.
Pour the granulated sugar into a 2-quart heavy-bottomed saucepan and place over medium-high heat. Cook, stirring occasionally with a wooden spoon, until the sugar melts and turns a light caramel color. Watch it carefully; once the sugar begins to caramelize, it can burn very quickly. When the sugar has melted and has turned a light golden brown color, slowly and carefully add the heavy cream. The addition of the cold cream to the hot caramel will cause the mixture to hiss and possibly splatter, so do not lean over the saucepan while you are adding it. When all of the cream has been added, mix thoroughly with a wooden spoon. Remember to mix into the edge of the saucepan where the caramel can stick. Add the milk and mix thoroughly. Add the chopped walnuts and mix until well combined and the walnuts are evenly dispersed. Insert a candy thermometer and cook over medium-high heat until the mixture reaches 225°. At this point, the caramel will have thickened and darkened slightly. Remove the saucepan from the heat and pour the filling into a heatproof bowl. Let cool.
Make the almond cream as directed in the recipe: Place the butter, sugar, and almond flour in a medium-size mixing bowl and beat with an electric mixer set on medium speed until light an fluffy, about 5 minutes. The mixture will be dry and sandy until the butter begins to incorporate. Add the egg and mix well. Use the rubber spatula to scrap down the side of the bowl as needed. The egg is well incorporated when the mixture is light and creamy, about 3 minutes. The batter lightens in color and increases in volume due to the incorporation of air by mixer. Add the all-purpose flour and beat on low speed until it is no longer visible, about 30 seconds. If you overmix, gluten will overdevelop and the almond cream will lose its delicate texture when baked. Sometimes Torres likes to add a splash of dark rum for extra flavor. You will use the almond cream right away, so there is no need to refrigerate it. If using refrigerated almond cream, allow it to return to room temperature. Beat it with an electric mixer set on medium- high speed until it returns to its original volume and is once again light in color. Preheat the oven to 375°.
Remove the dough from the refrigerator. Lightly give the dough a few quick raps with the rolling pin to soften it slightly. This will make it easier to roll. Lightly flour the work surface and each side of the dough. Roll the dough into a 12-inch circle about 1/4 inch thick. Transfer the dough to a 10-inch tart with a removable bottom pan by rolling it around the rolling pin. Unroll the dough over the tart pan. Gently press the dough into the pan, especially where the bottom and the side of the pan meet. Don't forget to press the dough up the side of the pan; this will help the dough hold its shape as it bakes. Remove any excess dough by rolling the rolling pin over the top of the pan to make a nice clean cut. Dock the bottom of the tart shell with a fork.
Spread about a 1/4-inch-thick layer of almond cream in the bottom of the tart shell. Peel the bananas and cut them into-inch- thick slices. Arrange the banana slices in concentric circles, starting at the edge of the tart shell and working your way toward the center. Leave about a 2-inch-diameter circle in the center of the tart. Fill this circle with the caramel-walnut mixture. Sometimes Torres likes to sprinkle granulated sugar over the tart just before baking; this gives the bananas a nice crust. Bake the tart until light golden brown and the filling forms a light crust, about 45 minutes. Remove from the oven and place on a wire rack until the tart has completely cooled.
Simply push up on the bottom of the tart pan and remove the side. Use a flat metal spatula to slide the tart onto a flat plate or platter. (If you use a plate with slightly raised edges, the tart will break.)
You can lightly dust the tart with powdered sugar before serving or top with apricot glaze.
Variations: This tart can also be made with peaches, apples, apricots, or figs. (Peel and core the apples.)