Bring 2 quarts of water to a boil. Add gizzards to boiling water, bring back to a boil, then reduce heat to medium low and simmer gizzards for 20 minutes.
Remove gizzards from water, let cool enough to handle.
While gizzards are cooling, preheat oven or toaster oven to 300 degrees Farenheit.
Slice gizzards 1/4" thick.
Toss gizzards in the olive oil and garlic powder.
Spread on baking sheet and bake for 1 hour, tossing 2-3 times.
Turn off oven and let gizzards dry in the oven for 1 hour.
Store in refrigerator for up to 3 weeks or freezer for 3 months.