01 -
Preheat oven to 350°F. Grease and flour a 9x13-inch baking pan.
02 -
In a large bowl, blend together mashed sweet potatoes, granulated sugar, brown sugar, vegetable oil, eggs, buttermilk, and vanilla extract until smooth.
03 -
In a separate bowl, sift all-purpose flour, baking powder, baking soda, salt, ground cinnamon, ground nutmeg, and ground ginger.
04 -
Gradually add sifted dry ingredients into the wet mixture, stirring gently until just combined.
05 -
In a small bowl, combine granulated sugar and ground cinnamon for the swirl.
06 -
Pour half of the cake batter into the prepared pan. Sprinkle half of the cinnamon swirl mixture evenly over the batter.
07 -
Pour the rest of the batter into the pan. Gently swirl the mixture with a knife and sprinkle the remaining cinnamon swirl over the top.
08 -
Bake for 35 to 40 minutes, or until a toothpick inserted in the center emerges clean.
09 -
Allow the cake to cool completely in the pan placed on a wire rack.
10 -
Whisk together powdered sugar, milk, and vanilla extract until smooth. Drizzle glaze evenly over the cooled cake.