3/4 cup (1 1/2 sticks) butter, melted, plus more for pan
3/4 cup packed light-brown sugar
1/4 cup granulated sugar
1 large egg
1/2 teaspoon salt
1/2 teaspoon ground cinnamon
1 cup all-purpose flour, (spooned and leveled)
2 cups old-fashioned rolled oats (not quick-cooking)
1 cup raisins
1 Pre-heat an oven to 180°C (350°F).
2 Grease an 8-inch square baking pan and line the bottom with parchment paper, leaving an overhang on two sides..
3 In a large bowl, whisk together butter, sugars, egg, salt, and cinnamon powder until smooth.
4 Add flour, oats, and raisins and mix together.
5 Spread the batter into the prepared pan, and bake for 25-30 minutes or until a toothpick inserted in the center comes out with clean, with light moist crumbs attached.