Career
Lappe had played in Bayern Munich"s youth system, but was released at a young age and went on to forge a career in amateur football in Bavaria. He ended the 2008-2009 season with eight goals in thirteen appearances for Ingolstadt II, finishing as the team"s joint top scorer with Stefan Müller. Lappe was the team"s top scorer both the 2009-2010 season (17 goals) and the 2010-2011 season (13 goals), as they finished in second place behind Football Club Ismaning – enough to earn promotion to the Regionalliga Süd, as Ismaning denied the opportunity to go up.
Ingolstadt II finished in seventh place in the 2011-2012 season, with Lappe scoring 18 goals - more than anyone else in the division.
This earned him a call-up to the first-team - he made four appearances in the 2. Bundesliga, his debut as a substitute for Ahmed Akaïchi in a 2–0 defeat against Turn- und Sportverein 1860 München in November 2011.
Lappe was not involved in the Ingolstadt first team at the beginning of the 2012-2013 season, but scored prolifically for the reserves, now in the Regionalliga Bayern, following a restructuring of the league. Bundesliga goal.