Italian Rainbow Cookies

Ingredients

• Cooking spray
• 1 (8-ounce) package almond paste (such as Solo)
• 1 cup granulated sugar
• 1 1/2 cups (12 ounces) unsalted butter, softened, divided
• 4 large eggs, separated
• 2 teaspoon almond extract
• 2 cups (about 8 1/2 ounces) all-purpose flour
• 1/4 teaspoon kosher salt
• Red liquid food coloring
• Green liquid food coloring
• 1/2 cup seedless red raspberry jam, divided
• 1 1/2 cups chopped (60% cacao) bittersweet chocolate (from 3 [4-ounce] bars)

Steps

1. Heat the oven to 325°F with racks in the top and lower thirds. Spray 3 (9- x 13-inch) baking pans or 3 small (9 x 12 1/2-inch) rimmed baking sheets lightly with cooking spray, line their bottoms with parchment paper, and set aside.
2. In a large bowl, use an electric mixer on medium to beat the almond paste, sugar, and 1/2 cup butter for about 1 minute, until combined. Add the remaining 1 cup butter and beat on medium for 2 to 3 minutes, until pale and fluffy. On low speed, add the yolks one at a time, beating just until combined after each. Beat in the almond extract on low just until combined, then gradually add the flour and salt on low, again beating just until combined. Set aside.
3. With clean mixer blades, beat the whites in a separate large bowl on high for 4 to 5 minutes, until stiff peaks form. Gently fold them into the batter in batches until fully combined. Divide evenly between 3 bowls, about 1 2/3 cups or 13 ounces in each. Stir red food coloring into the batter in the first bowl to reach the shade you want, then spoon that batter into the first prepared pan and spread evenly. Stir green food coloring into the batter in the second bowl to reach the shade you want, then spoon it into the second pan and spread evenly. Spoon the plain batter into the remaining pan and spread evenly. Put 2 pans in the upper third of the preheated oven without letting them touch and the remaining pan in the lower third. Bake for 10 to 13 minutes, until a toothpick in the centers comes out clean, exchanging the top and bottom pans halfway through. Cool completely in the pans on wire racks for about 30 minutes.
4. Spread 1/4 cup jam evenly over the cooled green layer in its pan. Invert the plain layer onto it and remove and discard the parchment. Spread the remaining 1/4 cup jam thinly over the plain layer. Invert the red layer on top and remove and discard its parchment. Cover the red layer with plastic wrap, place a used baking pan over the stack, and distribute weights such as plates or cans evenly on the pan. Refrigerate until firm, at least 4 hours or up to 12 hours.
5. Take off the weights, pan, and plastic wrap and invert the stack onto a cutting board. Remove and discard the parchment, then trim off and discard the edges with a serrated knife. Put the stacked cakes green-side up on a wire rack inside a large rimmed baking sheet and set aside.
6. In a medium-size heatproof bowl, microwave the chocolate on HIGH in 30 second intervals, stirring after each, until melted, about 1 minute and 30 seconds total. Spread over the tops and sides of the stacked layers. Cool slightly at room temperature for about 5 minutes, then scrape wavy lines into the chocolate with fork tines. Refrigerate uncovered for about 30 minutes, until set. Cut with a serrated knife into 24 (1 1/2- x 2 1/2-inch) rectangles. Store airtight at room temperature for up to 1 week.