It's great that you're exploring and experimenting with smoothie recipes! The reason you might not be able to taste the coffee in your smoothie, despite using a double espresso pod, could be due to several factors. Coffee, especially when used in the form of espresso, has a strong, distinct flavor that can easily be overpowered by other ingredients. The items you're including, such as frozen berries or bananas, vanilla protein yogurt, vanilla organic protein, and peanut butter, have prominent flavors that can mask the taste of the coffee. These ingredients not only have strong tastes but also contain natural and added sugars that can overshadow the bitterness of the coffee.

To enhance the coffee flavor in your smoothie, you could try increasing the amount of coffee or using a concentrated coffee form like cold brew concentrate, which might stand up better against the other robust flavors. Additionally, adjusting the balance of ingredients to reduce the quantity of those with dominant flavors, or choosing flavors that complement rather than mask the coffee, might help. Experimenting with the ratios can lead you to a mix where the coffee flavor comes through more strongly to your liking.

I'd try replacing the oat milk for coffee. You'll still have the creaminess from the protein powder, yogurt and bananas.