count same as aggregates returns single value so
// you try to call method sum on number and it fails
DB::table('orders')->where('user_id', $userProfile->id)->count()->sum();
you can make two requests to get sum and count but its not a good idea, or get data in collection and let it do the math
// not a good idea
//$count = DB::table('orders')->where('user_id', $userProfile->id)->count();
//$sum = DB::table('orders')->where('user_id', $userProfile->id)->sum('total_including_vat');
//collection way
$orders = DB::table('orders')
->where('user_id',$userPorfile->id)
->get(['id', 'total_including_vat']);
$result = [
'order_count' => $orders->count(),
'orders_total' => $orders->sum('total_including_vat')
];
or the same result as for your working example with mix raw expressions
$result = DB::table('orders')
->where('user_id', $userProfile->id)
->selectRaw('count(1) as order_count, sum(total_including_vat) as orders_total')
->first();