Quick-cook oats add extra fiber and texture to this rich chocolate dessert from Kathleen King, owner of Tate's Bake Shop.
Preheat oven to 350 degrees. Lightly butter a 9-inch square pan; set aside.
In a medium bowl, whisk together flour, oats, baking powder, and salt; set aside. In a glass measuring cup, whisk together heavy cream and espresso; set aside.
In the bowl of an electric mixer fitted with the whisk attachment, mix together butter and brown sugar until light and fluffy, about 3 minutes. Add eggs, one at a time, mixing well after each addition and scraping down sides of bowl as necessary. Beat in melted chocolate.
With the mixer on low, add flour mixture in three additions, alternating with cream mixture, beginning and ending with flour mixture. Beat until smooth, scraping down sides of bowl as necessary.
Transfer batter to prepared cake pan, spreading evenly. Transfer to oven and bake until a cake tester inserted into the center comes out clean, 25 to 35 minutes. Transfer to a wire rack to cool completely. Serve with Nutella Whipped Cream.