The Kidlet and I made this cake to take to Thanksgiving. It is a very rich, dense cake full of oatmeal and chocolate. And the peanut butter icing adds even more decadence.

Oatmeal Chocolate Chip Cookie Cake with Peanut Butter Frosting

Slightly adapted from C&C Cakery

Ingredients

Cake

• 1 c. rolled oats
• 1/2 c. unsalted butter
• 1 1/2 c. boiling water
• 225g dark chocolate chips (or coarsely chopped dark chocolate)
• 1 1/2 c. + 2 Tbsp. all-purpose flour, divided
• 2 large eggs
• 1/2 c. sugar¹
• 1 c. brown sugar
• 1/2 Tbsp. ground cinnamon
• 1/4 tsp. coarse sea salt, ground
• 1 tsp. baking soda
• 1 tsp. baking powder
• 1 tsp. vanilla extract

Frosting

• 1 1/2 c. peanut butter
• 1/2 c. unsalted butter, softened
• 1/2 Tbsp. vanilla extract
• 1/2 tsp. coarse sea salt, ground
• 200g icing (powdered/confectioners') sugar²
• 3/4 c. heavy (35%) cream, whipped

Directions

1. Preheat oven to 190°C (375°F) and grease a 23x33cm (9x13") cake tin/baking dish.
2. Place the stick of butter with the oats, pour over the boiling water, and let stand for 1 minute.
3. Stir the oat mixture to thoroughly combine and let stand until cooled.
4. Meanwhile, toss the chocolate with 2 Tbsp. of the flour and set aside.
5. Beat the eggs with the sugar, brown sugar, cinnamon, salt, baking soda, baking powder, and vanilla.
6. Add the oat mixture once cooled and stir to combine.
7. Mix in the remaining 1 1/2 c. of flour.
8. Stir in the flour-coated chocolate chips.
9. Pour the batter into the prepared pan and spread into an even layer.
10. Bake at 190°C (375°F) for 35-45 minutes.
11. Allow to cool completely before icing.
12. Beat the peanut butter with the butter until light and fluffy.
13. Mix in the vanilla and salt.
14. Gradually sift in the icing sugar while continuing to beat vigorously.
15. Fold in the whipped cream.
16. Spread the icing evenly over the cooled cake.

---

¹ The original recipe called for 3/4 c. sugar and 1 1/4 c. brown sugar. I used the full amount of granulated sugar, but only 1 c. of brown sugar this time around. The cake came out great, but I'd be tempted to try it with slightly less sugar next time. Maybe just 1/2 of granualted and 1 c. of brown. And, if that works well, I'd be tempted to omit the granulated sugar altogether on future attempts and just roll with 1 1/4 c. of brown sugar. That said, I didn't want to adjust things too much too fast. Hence the incremental approach. ^Back
2 The original recipe called for 2 c. of icing sugar. I weighed my sugar and found it came in at ~125g/cup. So I used ~250g of icing sugar for my frosting. That said, I found it a little sweeter and stiffer than I'd ideally like, so I think I'd aim for closer to 200g of sugar next time. ^Back