Rosemary, Olive Oil and Orange Cake

INGREDIENTS

Rosemary, small sprigs

1 1/2 tbsp

Rosemary, packed leaves

Egg white

Eggs, large

2 1/2 tsp

Lemon juice, freshly squeezed

2 cups

All-purpose flour

2 tsp

Baking powder

1 3/4 cups

Confectioners' sugar

2 tsp

Granulated or superfine sugar

1/4 tsp

Salt

1/2 cup

Superfine sugar

3/4 cup

Olive oil, extra-virgin

1 1/2 tbsp

Orange juice, freshly squeezed

2 tbsp

Butter, unsalted

1/2 cup

Sour cream

1 tablespoon finely grated orange zest (from about 1 1/2 oranges)