Preheat oven to 350F.
In a large bowl, beat the eggs for a minute, until frothy. Beat in the sugar and continue to beat for a few minutes, until the mixture is thick and pale. Beat in the lemon zest, juice and olive oil.
In a small bowl, combine the flour, baking powder and salt. Add it to the egg mixture and stir by hand until almost combined; add the rosemary and pears (if you're using them) and stir just until blended.
Pour into an 8"x4" or 9"x5" loaf pan that has been sprayed with nonstick spray. Lay a couple sprigs of rosemary on the top.
Bake for about 45 minutes, until golden and springy to the touch.