Preheat oven to 350°F and spray an 8½ x 4½-inch loaf pan with nonstick cooking spray.

In a bowl, beat eggs, sugar, sour cream, lemon zest, lemon juice, and lemon extract until creamy. Gradually add oil and mix well.

In a separate bowl, whisk together flour, baking powder, and salt.

Add dry ingredients to wet ingredients and mix until just combined. Set aside.

In a medium bowl, beat cream cheese until smooth and mix in confectioners' sugar.

Pour half of the batter into the prepared pan, add half of the cream cheese mixture, and swirl to create a marbled effect.

Add remaining batter and top with remaining cream cheese mixture. Swirl gently.

Bake for 75 minutes or until a toothpick inserted in the center comes out clean. Cool before serving.