In a medium bowl, combine cream cheese, sugar, 1 tablespoon flour, egg and orange zest; beat until smooth. (Be sure to use the measurements found under filling for these.) Set aside.
Stir together the glaze ingredients and set aside.
For the bread:
Cream butter and sugar (1/2 cup) until fluffy. Add salt and vanilla. Add egg yolks (save the egg whites as you’ll need them later) to the sugar mixture; beat until creamy. Set aside.
In another bowl, combine flour (1 1/2 cups) and baking powder. Add this mixture, alternately with milk to egg yolk mixture.
Coat berries with 1 tablespoon flour and add them to the batter.
In a separate bowl, beat egg whites until soft peaks form. Add sugar (1/4 cup), 1 tablespoon at a time, and beat until stiff peaks form. Fold egg whites into batter.
Pour 1/2 of the batter (or a little less) into a floured and greased bread pan. Layer the filling over the batter and then finish with remainder of batter. This will create a layer of “cheesecake” between the blueberry batter.
Pour glaze over top of unbaked loaf and bake at 350F for 55-60 minutes.