You could do:
. <( sed 's/^\$ //' <<'PASTE'
**paste here**
PASTE
)
Or, make that into a function:
undollar() { . <( sed 's/^\$ //' ); }
Than you use that like
$ undollar<hit enter>
<paste here>
<hit Ctrl+D>
Both of these approaches use the .
command, so effects are seen in the current shell: for example with the commands you list, the FLASK_APP and FLASK_DEBUG environment variables remain in the shell.
As noted by Charles Duffy, old versions of bash cannot source a process substitution: see Why source command doesn't work with process substitution in bash 3.2?