Instructions

for the candied almonds

 Line rimmed baking sheet with parchment paper. Melt butter in 12-inch nonstick skillet over medium heat. Add almonds and cook, stirring frequently, until light golden brown, about 5 minutes. Add sugar and continue to cook, stirring constantly, until sugar has caramelized and almonds are deep golden brown, about 3 minutes longer. Transfer to prepared sheet, spread in even layer, and let cool completely.

for the filling

 Whisk egg yolks, 2 tablespoons sugar, and cornstarch in medium bowl until mixture is pale yellow and thick, about 1 minute; set aside. Heat 2 cups cream, salt, and remaining 6 tablespoons sugar in medium saucepan over medium heat until simmering, stirring occasionally to dissolve sugar.
 Gradually whisk half of cream mixture into yolk mixture to temper, then slowly whisk tempered egg yolks back into simmering cream mixture. Return to simmer over medium heat and cook, whisking constantly, until pastry cream is thickened and a few bubbles burst on surface, about 1 minute. Off heat, whisk in butter, vanilla, and almond extract until incorporated. Transfer pastry cream to bowl and press plastic wrap directly on surface. Refrigerate pastry cream until cold and set, at least 3 hours or up to 2 days.

for the frosting

 Transfer 1 cup pastry cream to small bowl for frosting and let come to room temperature. Using stand mixer fitted with paddle, beat butter on medium speed until smooth and light, about 3 minutes. Add pastry cream in 3 additions, beating for 30 seconds after each addition. Add amaretto and continue to beat until light and fluffy, about 5 minutes longer, scraping down bowl as needed. Set aside frosting.
 Using clean, dry mixer bowl and whisk attachment, whip remaining 1/2 cup chilled cream on medium-low speed until foamy, about 1 minute. Increase speed to high and whip until soft peaks form, 1 to 3 minutes. Using rubber spatula, fold whipped cream into remaining pastry cream; set aside filling.

for the cake

Using long serrated knife, cut 1 horizontal line around sides of each cake layer; then, following scored lines, cut each layer into 2 even layers. Spread each bottom cake layer with 1 cup filling and replace top. Line edges of cake platter with 4 strips of parchment to keep platter clean. Place 1 filled cake on platter. Top with remaining filling and place second filled cake on top. Spread frosting evenly over top and sides of cake. Gently press candied almonds all over cake. Dust top of cake with confectioners' sugar and carefully remove parchment strips before serving.