Yes you can freeze Streusel Topping and it will be just fine.
When freezing Streusel Topping cover the Streusel Topping with plastic wrap or put the Streusel Topping in a freezer safe container.
The Streusel Topping should last for up to 3 months in the freezer but it's best to use the leftover Streusel Topping within a few months or sooner so that it's even more fresh.
You can also store the Streusel Topping in a plastic bag as well.
When you need to store crumble topping or Streusel Topping you should freeze the crumble topping for best results.
When freezing crumble topping the crumble topping should be stored in a freezer proof airtight container or tightly sealed in a freezer bag.
You can keep the frozen crumble topping for at least 3 months.
The crumble topping will be okay after 3 months in the freezer but for best results with the crumble topping you should use the frozen crumble topping within the 3 months.
The longer the crumble topping stays frozen the less fresh it becomes.
So use the crumble topping within 3 months of freezing it.