Banana Crunch Cake

I was in the mood to bake today and had bananas to use up. So I used them in making Valerie's Banana Chocolate Chip Muffins (though I made some High Altitude changes and they turned out even better than last time) and this Banana Crunch Cake from King Arthur Flour's Whole Grain Baking cookbook. You can see both of my efforts in the picture. I did make the following High Altitude changes: add 1 Tbsp. flour, change baking soda to 3/4 tsp., subtract 1 Tbsp. brown sugar, and add 1 1/2 Tbsp beaten egg. I baked it in a 9" round cake pan at 375 and it took about 40 minutes. I also used the bake-even cake strips around the cake pan. I used wheat pastry flour and you can make the oat flour by putting quick or old fashioned oats in a blender or food processor and processing until it is flour. Here's the original recipe. I thought it was pretty tasty and was just sad we didn't have any vanilla ice cream to go with it.

Cake batter
1 cup (3-1/4 oz) oat flour
1 cup (4 oz) whole wheat flour, traditional or white whole wheat
1 teaspoon baking soda
1/2 teaspoon salt
1/2 cup unsalted butter
2/3 cup (5 oz) packed light or dark brown sugar
2 large eggs
1 cup (8 oz) mashed banana (2 large or 3 medium bananas)
1/2 cup (4 oz) plain yogurt, non-fat to full-fat
1 teaspoon vanilla
1/2 cup (1-7/8 oz) chopped pecans or walnuts
1 cup (6 oz) chocolate or toffee chips (optional)

Crunch topping
3/4 cup (2-5/8 oz) old-fashioned rolled oats
1/3 cup (2-1/2 oz) packed light or dark brown sugar
1/2 teaspoon ground cinnamon
1/4 teaspoon salt
2 Tablespoons unsalted butter, melted
1/4 cup (1 oz) chopped pecans or walnuts

Grease and flour an 8-inch square pan. Preheat oven to 350 degrees.
To make the cake batter: Whisk together the flours, baking soda and salt in a medium bowl. Cream together the butter and sugar in a large mixing bowl until light and fluffy. Beat in the eggs, one at a time, stopping to scrape the sides and bottom of the bowl between additions. Mix in half the dry ingredients until moistened, then mix in the bananas, yogurt and vanilla. Scrape down the sides and bottom of the bowl, then add the remaining dry ingredients and the nuts and chips, if using, mixing until evenly moistened. Transfer the batter to the prepared pan.
To make the topping: Combine the oats, brown sugar, cinnamon and salt in a small mixing bowl until well blended. Stir in the melted butter until the moisture forms large crumbs; stir in the chopped nuts. Sprinkle the topping over the batter in the pan.
Bake until the edges pull away from the pan and a cake tester inserted in the center comes out clean, 40-45 minutes. Remove the cake from the oven and place on a rack to cool for 20 minutes before serving warm, with ice cream, or cool completely for later use. Yield: 16 servings