Pecan Streusel Banana Bread

Ingredients

• 2 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1/2 cup (1 stick) unsalted butter, softened
• 1 cup sugar
• 2 large eggs, at room temperature
• 1 teaspoon vanilla extract
• 1 teaspoon finely grated lemon zest
• 1 cup mashed ripe banana (about 3 medium or 2 large bananas)
• 1/2 cup sour cream, at room temperature