Step 1

Cook the frozen berries, sugar and zest in a small saucepan over medium-low heat until they are tender and the sugar dissolves, about 5 minutes. Blend the berries with a blender or immersion blender until pureed.

Step 2

Preheat oven to 350°F. Grease an 8x3-inch Springform Cake Pan and line the bottom with parchment.

Step 3

In a food processor, mix together the graham crackers, brown sugar, salt, and butter. Pour the mixture into the prepared pan and press it out in an even layer. Bake for about 12 minutes, until it starts to look lightly toasted. Lower oven to 325°F.

Step 4

In a stand mixer fitted with the paddle attachment, mix the cream cheese on medium speed for about 1 minute. Scrape down the sides and mix for another 30 seconds. Add the sugar and mix for about 1 minute, scrape down the sides of the bowl. Mix in the creme fraiche and ricotta until smooth. Add the eggs one at a time, scraping down the sides after each. Add the vanilla, lemon extract, zest and salt. Mix for 30 seconds.

Step 5

Pour 1/3 cheesecake batter over the baked crust. drizzle 3 tablespoons blueberry sauce over the batter. Use a skewer or knife to gently swirl the sauce into the batter. Pour half of the remaining cheesecake over the swirled blueberry sauce, repeat the swirling with 3 tablespoons blueberry sauce. Add remaining cheesecake batter and finish by swirling 3 tablespoons blueberry sauce on top.

Step 6

Bake cheesecake on a cookie sheet in the center of the oven for about 75-90 minutes (the timing will greatly depend on the temperature of the ingredients). Place a second sheet on a lower rack and fill with boiling water. The cheesecake will soufflé as it bakes, which is normal for this style baking. Once the top of the cake is set, remove from the oven and gently run a knife blade around the edge of the pan. Allow to cool to room temperature before refrigerating.

Step 7

Chill for several hours or overnight. Run a hot knife blade around the outer edge of the cake, then remove the sides of the springform pan. Lay a piece of plastic over the top and invert the cake to remove the bottom of the pan and parchment paper. Invert the cake onto the serving plate.

Step 8

Top with whipped cream and berries before serving. I used a Leaf Decorating Tip to make the ruffles. Serve with remaining blueberry sauce.