I was one of those teenagers that thought coffee cake actually tasted like coffee, and since I didn't like coffee yet, I presumed I didn't like coffee cake. It was a sad, sad time. One night I was hanging out with two of my friends who had just come back to the store with a red box of Aunt Jemima coffee cake mix. Even then, seeing that coffee didn't make an appearance in the ingredients, I was still skeptical. Then I took a bite, and the brown sugar crumble topping won me over. I made that cake for years, from the box, whenever I craved it. Then I started cooking, learned to bake, and well, I'm sure you can see where this is going.
This past Christmas I thought long and hard about which cookbooks I wanted, and Good to the Grain by Kim Boyce rose to the top of the list. I'd had it saved in my Amazon wish list for years, and was finally ready to embrace cooking with whole grain flours. In fact, now that I prefer whole grains, the timing was right. I have to tell you, this cookbook is a game changer for me, and I'm so excited to cook through it this year. It's well written, beautifully styled, and full of inspiration for bringing more flavor and health to your favorite baked goods. (Also, did you know you can make cereal from scratch? Cereal! If you've read about my addiction, you can only imagine how exciting this is.)
In this case, I stumbled across a wonderful note in the sidebar of one of Kim's muffin recipes. She explained that all muffins could be easily turned into coffee cakes by pouring the batter into a cake pan instead of muffin tins. That was all I needed to know.
SWEET POTATO COFFEE CAKE
I have a habit of not sifting dry ingredients when I bake, but I'm determined to change it. Don't skip this step, it will ensure a tender crumb. Also, this cake stays moist for days, so enjoy a slice with your afternoon tea all week.
Recipe slightly adapted from Good to the Grain by Kim Boyce
2 small or 1 large sweet potato, about 3/4 pound
1 cup whole wheat flour
1 cup all purpose flour
1 tablespoon cinnamon
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon kosher salt
1/2 teaspoon nutmeg
1/4 cup cold unsalted butter (1/2 stick)
1/4 cup sugar
1/4 cup brown sugar
1 cup buttermilk
1/2 cup plain yogurt
6 large Medjool dates, pitted and finely chopped
3/4 cup brown sugar
1/2 cup walnuts, chopped
Preheat the oven to 400 degrees. Prick the sweet potato with a fork and bake for 1 to 1 1/2 hours, until they're tender and the skin is dark. Set aside to cool, then peel and leave whole.
Lower the oven to 350 degrees and butter a 9-inch square cake pan.
Sift the dry ingredients into a large bowl. In a small bowl, whisk together the buttermilk and yogurt.
To the bowl of a standing mixer fitted with the paddle attachment, add the butter and sugars. Beat on high speed until they are light and creamy, about 3 minutes. Reduce speed to low; add half of the sweet potato and the egg and mix until just combined. Scrape down the sides of the bowl.
Add the dry ingredients and mix until partially combined. Add the buttermilk mixture and mix until combined. Add the remaining sweet potato and mix until barely combined (you want chunks to still be visible). Fold in dates with a spatula, then spread evenly into the prepared cake pan.
In a small bowl, combine the brown sugar and walnuts and sprinkle evenly over the cake. Bake for 35-45 minutes, until slightly golden and a toothpick comes out clean.