Oatmeal Lemon Crumble Bars

Bahan-bahan (16 porsi)

• 7 Tablespoons (99g) unsalted butter, softened to room temperature (yes, 7 Tbsp!)
• 3/4 cup (150g) packed light or dark brown sugar
• 1 teaspoon pure vanilla extract
• 1 cup (125g) all-purpose flour (spooned & leveled)
• 1 teaspoon baking powder
• 1/4 teaspoon salt
• 1 cup (85g) old-fashioned whole oats or quick oats (not instant)
• 1 (14-ounce weight) can full-fat sweetened condensed milk
• 6 Tablespoons (90ml) lemon juice (about 2 lemons)
• 1 Tablespoon lemon zest (about 1 lemon)