Create a version of Syrup Pools that burn up the CAKE while you are receiving the token rewards. So instead of simply trading the CAKE for the other token you want, you burn it up in an Inferno Pool. At the end of the burn, maybe over a few months, you have 0 CAKE in return for X tokens.
This gives the recipient the benefit of dollar-cost-averaging and limits supply / increases the price of CAKE in the long run.
I believe the required "APR" to make this work as a one-for-one value exchange over one year is around 700%. That may sound high, but remember you are losing CAKE while you burn, so most of it is burned up after a couple months. Really, the APR doesn't matter because it is essentially just a very drawn-out trade. But it's an enticing way to burn cakes!
We could also sweeten the deal by offering a bonus, like 10-20% more of the rewarded token if you burn instead of trade.