In a food processor add your lady finger cookie and pulse until fine crumbs are produced. Add your 2 tbsp softened butter, and pulse again until just mixed.
Butter and Flour a 9" spring foam pan and then add the butter crumb mixture to bottom of pan. Press down into pan and then set aside.
Next using an electric mixer, add your six egg whites (that have already been separated), salt and cream of tartar. Whisk first for one minute on low speed until eggs are frothy, and then bring speed up to medium and whisk until soft peaks form. Set aside.
In a large bowl add your ricotta, mascarpone, sugar, flour and egg yolks. With an electric mixer, mix over medium speed until mix is light and fluffy. Add your vanilla bean and egg whites. Fold into mix.
Place cheese filling into spring foam pan, being sure to smooth and level out top. Place in oven for 1½ hours or until top turns a nice golden yellow / brown and is firm to touch.
Remove from oven and set on a wired rack to cool for about 1 hour room temperature, and then at least 2 hours in the fridge.
For the Sauce
While the cheesecake is cooling begin your sauce.
In a small pot add your water and granulated sugar, bring to a boil.
Add your rhubarb and raspberries (halved and whole), reduce heat to medium and continue to cook for about 5-8 minutes. Once the rhubarb has reached a soft texture remove sauce from heat and let cool. Place in fridge until ready to use (the sauce will begin to thicken as it cools).
Assembly
Carefully remove cake from spring foam pan and pour sauce on top. Serve.
Recipe by My Lavender Blues at https://mylavenderblues.com/italian-cheesecake-with-a-rhubarb-raspberry-sauce/