A specific blessing for matzah only said on Seder night is now said:

Baruch atah Adonai, Eloheinu Melech ha'olam,
Asher kid’shanu b’mitzvotav v’tzivanu al achilat matzah.
Blessed are You, Lord our God, King of the Universe,
Who has sanctified us in His commandments and commanded us to eat matzah.

[The matzah is passed among the Seder participants and eaten. The serving can be supplemented by extra pieces of matzah.]

haggadah Section: Motzi-Matzah