Yeah, these broccoli plants are 'bolting'. What fertilizer did you use? This is found when too much nitrogen is added, lots of vegetative growth and the reproductive growth bolts. OR, when there are a few too many days of drastic temperature changes, up or down, that will cause this 'bolting'.
The most common problem is too much nitrogen in relation to Phosphorous and Potassium. Adding raw compost for example.
Harvest when small, they will be delicious. Check your fertilizer program. What has been happening with your weather? What soil is in these raised beds? How were these raised beds made? What have you added in terms of compost, chemistry? I've never seen such healthy broccoli leaves...that tells me you've used too much nitrogen. Let me know okay?