I see this issue marked as solved, but I wanted to share my own experience as an additional solution. I am still using 19, but I imagine it would be the same in the newer versions.

I start with a basic Find report (control+F). Set transaction type as Build Assembly. Set desired date range. Set Detail Level to Summary Only. Click "Find" to generate results. Click "Report" to generate a default report.

Click "Customize." Under Columns, un-check the following: Name, Number, Memo, Account, Class, Clr, Split, Debit, Credit, and Balance. Under Columns check the following: Item & Quantity. Change "Sort By" to Date and Sort Order to Ascending. Click OK.

This should give you what you wanted. Of course you can further customize as desired.

Keep in mind this report does not include any Builds which have been flagged as Pending. If your Items include sub-assemblies, these will also be included in the report.