Start by melting the unsalted butter in a medium skillet over medium heat. Keep a close eye as it foams and then begins to brown, releasing a warm, nutty aroma. This usually takes about 4-5 minutes. Once it turns a golden brown color with toasted bits at the bottom, remove the skillet from heat to prevent burning.
Peel and slice your 4 ripe pears into even pieces. Place them in a mixing bowl and add the 1/2 teaspoon vanilla extract and a sprinkle of cinnamon if you like an extra touch inside the fruit. Toss gently to coat the pears evenly.
In a separate bowl, combine 1 cup rolled oats, 1 cup brown sugar, 1/2 cup all-purpose flour, 1 teaspoon ground cinnamon, 1/4 teaspoon salt, and 1/2 teaspoon baking powder. Pour the warm brown butter over the dry ingredients and stir until the mixture is crumbly and well coated.
Preheat your oven to 350°F (175°C). Spread the sliced pears evenly in your baking dish. Sprinkle the brown butter oat topping generously over the pears, covering them completely. Bake for 35-40 minutes or until the topping is golden and crisp and the pears are bubbling and tender.
Let the crisp cool slightly before serving. This dessert is divine on its own or paired with a scoop of vanilla ice cream or a dollop of whipped cream. For a fresh contrast, serve alongside a Pear And Gorgonzola Spinach Salad for a full pear-themed meal.