The incomparable flavor of pure maple syrup is reason enough to make this sweet treat; that it is also quick to prepare is an added bonus. Maple syrup is marked and graded by its color, ranging from light to dark — the darker the color, the more intense the flavor. If you can find grade B, use it here for both the batter and the icing.
For the Cake
1 cup (2 sticks) unsalted butter, room temperature, plus more for pan
2 1/2 cups all-purpose flour, plus more for pan
2 teaspoons baking powder
1/2 teaspoon baking soda
1/2 teaspoon coarse salt
3/4 cup pure maple syrup
1/2 cup granulated sugar
2 large eggs
1 teaspoon vanilla extract
3/4 cup sour cream
For the Icing
1/3 cup pure maple syrup, plus more if needed
3 tablespoons unsalted butter, melted
2 1/2 cups confectioners’ sugar, plus more if needed
Make the cake: Preheat oven to 350 degrees. Butter a 9-inch square baking pan; line with parchment, and butter parchment. Dust with flour, tapping out excess. In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
With an electric mixer on medium speed, beat butter, maple syrup, and granulated sugar until pale and fluffy, 3 to 5 minutes. Add eggs, one at a time, beating well after each addition; mix in vanilla.
Reduce mixer speed to low. Add flour mixture in 3 batches, alternating with 2 batches of sour cream; beat until just combined. Transfer batter to prepared pan; smooth top with an offset spatula. Bake until a cake tester comes out clean, about 40 minutes. Transfer pan to a wire rack to cool 10 minutes. Turn out cake onto rack to cool completely.
Make the icing: Combine maple syrup and butter in a bowl. Sift in confectioners sugar, and whisk until combined. Adjust consistency with more syrup or sugar, if necessary. Spread maple icing over top of
– Martha Stewart