They are delicious!
though feel free to attach your own significance
Here is My favorite reason:
The passuk says
אִם־יִֽהְי֨וּ חֲטָאֵיכֶ֤ם כַּשָּׁנִים֙ כַּשֶּׁ֣לֶג יַלְבִּ֔ינוּ אִם־יַאְדִּ֥ימוּ כַתּוֹלָ֖ע כַּצֶּ֥מֶר יִהְיֽוּ׃
“ Be your sins like crimson, They can turn snow-white; Be they red as dyed wool, They can become like fleece.”
The red meat is covered up by the white dough. Much as we hope all our aveiros shall be.
May The Ribono shel olam be moichel our aveiros in keeping with Yeshaya’s nevua and in the zechus of our keeping the Mitzvos Hayom including eating in general and including minhaggim like the eating of the helige kreppel may all of Klal Yisroel have a Gemar Chasima Tova