Mix the flour and baking powder together and sift.
In a separate bowl whisk together eggs, sugar, salt, zest, vanilla extract, mascarpone and ricotta.
Whisk the flour into the wet ingredients until fully incorporated.
Using a 2 ounce ice cream scoop, scoop one at a time into a large pot filled with oil set to 350 degrees and fry for 5 to 7 minutes.
In a bowl, mix together the heavy cream, mascarpone and powdered sugar. Put mixture in the iSi canister and charge with 2 charges of gas. Dust the doughnuts in powdered sugar, plate with the strawberries and the whipped cream from the canister.