I might even try adding ginger in chocolate cake batter in the future! (lecoindemel.com)
Gently place the one tablespoon of nut butter in the center of the batter, and top with the remaining chocolate cake batter so you can't see the nut butter anymore. (beamingbanana.com)
The stripes are achieved by alternating spoonfuls of yellow and chocolate cake batter into a pan. (easydessert.org)