Ok, you talked me into it. You got a few good suggestions already, let’s see if we can help a little more. First, @Alisa tells you to check the flavor usage. This is important. If you put 10% of a flavor in a mix that turns out to be a extremely strong and is recommended no more than 2%, just how do you think that will turn out? As far as your percentages go you will need to decide what your most dominant flavor should be in this mix, Butterscotch or Oatmeal cookie. All other flavors will be accents if you choose to add them. These accents would be at low percentages so as not to dominate in any way. @JoJo says FW Butterscotch is better, actually, it’s probably the best. She also says Malted Milk can overpower a mix. This is ABSOLUTELY correct. Use Malted milk at no more than 2% in mixes you do not want a dominant Malted Milk Flavor.
I recommend you drop Brown Sugar and the Dairy Milk. These are unnecessary. I really like the taste of Malted Milk in a mix and can see a possible benefit for this mix. Again choose the dominant flavor then make this dominant flavor a little stronger than the secondary flavor. Then add your 2% or less Malted Milk.
Now I want you to understand that even those of us who have been blending a long time can rarely create a recipe and get it the way we want the first time. Honestly it usually takes me 2-5 times to get it right but be aware, even I will scrap a idea because it just doesn’t work out. This can happen to any of us so do not get discouraged if it happens to you. Creating flavors is a hit and miss thing since your taste buds set the ground rules. You will have to make adjustments up and down on the percentages until you get it the way you like it.
Be aware there are two ways to create ejuice flavors. One as you are doing with this project, choose some taste (usually foods, drinks, ect) to duplicate. This may actually be the hardest way to create. The second way to create is to use FOOD PAIRING to choose flavors that mix well together and blend them. This method does not require a duplication of a specific taste. This method can produce new and exciting flavors you would have never thought of. Many of my juices were just a thought of a few flavors that mixed well together and next thing you know, it was a Ejuice. Which ever method you choose to create just be sure to know, hitting it the first time is rare, and practice makes perfect…