Apparently not. This blog discusses the current impossibility of the synchronized alarms. I couldn't find any information that suggests that they changed it by now. However as the blog discusses, it means that you can set one alarm and one timer per Echo, which multiplies your available timers and alarms. Alas, that's not your goal.
I checked the usual suspects, but IFTTT does not offer the that-branch for Alexa. It also seems to be incapable of just playing your voice back and thus making the voice output of the one Alexa the input of the other one. However that would mean a delay for a timer, since timers are relative times. Moreover, this would only work with different wake words, since otherwise the Echos don't react both (cf. This blog). Only the nearest will respond. That also eliminates the possibility to just speak somewhere where all Echos can hear you.
If you have more than one device using the same wake word, Alexa responds intelligently from the Echo you're closest to with ESP (Echo Spatial Perception), and performs the requested task.
(Amazon Documentation, emphasis mine)
The page also confirms that the alarms are device specific.
Some content is not common between devices on the same account, including:
- Alarms and timers
- Bluetooth connections
The following solidifies even more that there is no off-the-shelf solution for the dual alarms.
Note: You cannot connect multiple Alexa devices to each other and play the same requested audio at the same time.
Of course you can use the app to set the alarm from wherever you are and can set it for each Echo. Still, that means setting the alarm twice. Currently, I see no option to easily set the alarm automatically on both (or all) Echos.
(Update: you can select which echo to set the alarm or timer on by selecting it in your voice command and do not need to use the app.)
For example: "Alexa, set a timer to go off in an hour in the kitchen." Would effectively set the timer to only go off in the kitchen.