Upvote:2
Yes, you can.
From the Berlin Service Portal:
this case, the residence permit and all supplementary regulations (also regarding the stipulations concerning gainful employment) remain in force until a decision has been made in relation to the application. Journeys abroad and re-entry into the area of the Republic are possible with a valid [Fiktionsbescheinigung] in accordance with Β§ 81 Section 4 of the Residence Act.