Preheat oven to 350 degrees.
Butter the sides and bottom of a large 9 x 15" baking dish.
In a medium bowl, using a hand-held electric mixer, beat the eggs.
Add the sugar to the eggs and mix until pale and thick, about 2 minutes.
Beat in the vanilla extract, pinch of sea salt, and lemon zest.
Beat in the heavy cream.
Spread 1/3 of the bread cubes in the baking dish.
Scatter 1 cup of the mixed berries on top of the bread cubes.
Layer another 1/3 of the bread cubes on top of the berry layer.
Scatter the 2nd cup of the mixed berries on top of the bread cubes.
Layer the final 1/3 of the bread cubes on top of the berry layer.
Pour the egg/custard mixture over all of the bread cube and berry layers.
Press the bread cubes down into all of the custard sauce.
Sprinkle 2 Tbsp. of sugar all over the top.
Let the entire mixture sit at room temperature for 30 minutes to allow the bread to absorb the egg custard mixture.
Bake the bread pudding in the center of the pre-heated oven for 30 minutes, or until the top is golden and the custard is set.
Let cool for 30 minutes before cutting into and serving.
Serve with freshly whipped Limoncello whipped cream and fresh berries.