Lime Blueberry Tiramisu

• 1 pint heavy whipping cream
• 1/4 cup confectioners' sugar
• 1 pound mascarpone cheese, at room temperature
• 3 (3-ounce) packages unfilled ladyfingers
• 1 (6-ounce) can frozen limeade concentrate, thawed
• 1 (21-ounce) can blueberry pie filling 

In a large bowl, beat cream with an electric mixer at medium speed until thickened. Gradually add confectioners' sugar, beating until soft peaks form. Gently stir in cheese until combined; set aside.

Split ladyfingers in half. Line a 13 by 9 by 2-inch baking dish with ladyfingers, cut side up. Brush ladyfingers with limeade concentrate. Spoon half of cheese mixture over ladyfingers. Top with half of blueberry pie filling. Repeat procedure for the next layer with remaining ladyfingers, limeade, cheese mixture, and pie filling. Cover and chill 8 hours. Cut into squares to serve. Garnish with fresh mint, if desired.