Lemon and Blueberry Upside Down Cake

• Preheat oven to 350°F.

BLUEBERRIES

• Combine the brown sugar and butter in a 9 inch diameter cake pan with 2 inch high sides (preferably nonstick).
• Place the cake pan over medium heat and whisk constantly until butter and sugar melt and mixture is smooth and bubbling. Using pot holders, remove the pan from heat; cool 15 minutes. Sprinkle the blueberries evenly over.

CAKE

• Sift the flour, baking powder, and salt into a medium bowl.
• Combine the almond paste, sugar and lemon zest in the bowl of stand mixer fitted with paddle attachment. Beat on medium speed until the almond paste is broken into very small pieces, about 1 minute. Add the butter, 1 piece at a time, beating until mixture is smooth and scraping down sides of bowl occasionally. Add eggs, 1 at a time, beating well and scraping sides of bowl after each addition. Add the flour mixture and beat just until batter is smooth.
• Spoon the batter in dollops over the blueberries in the pan; spread evenly with spatula to smooth.
• Place some foil or a pan on a rack under the cake to catch any possible exploding juices from the blueberries (just in case).  Bake the cake until deep golden and tester inserted into center comes out clean, about 42 minutes. Remove from oven; let stand 1 minute. Run a small knife around cake to loosen. Place a large platter atop pan. Using oven mitts or pot holders, hold platter and cake pan firmly together with both hands and invert; shake gently, allowing cake to settle on platter. Cool at least 20 minutes.
• Serve warm or at room temperature with additional blueberries and whipped cream, if desired.