Create two server environments, one for port 80 (http) and one for port 443 (https). Have the http environment do nothing but redirect to the other one:

server {
        listen 80;
        listen [::]:80;
        server_name yesterdayscoffee.de www.yesterdayscoffee.de;
        return 301 https://$server_name$request_uri;
}
server {
        listen 443 ssl;
        listen [::]:443 ssl;

... all the rest of your configuration

}