In a large bowl, whisk together flour, baking powder and salt.

In a separate bowl, mix together eggs, sugar, melted butter, yogurt and vanilla until well combined.

Mix flour mixture into wet mixture until thoroughly combined and no lumps remain, about 1 minute.

Gently fold in peaches until evenly distributed.

Cover the bowl with plastic wrap and let batter rest at room temperature for 20 minutes (no longer than 30 minutes)

While batter rests, preheat oven to 375 degrees and line a 12 cup muffin tin with paper liners OR spray with with canola oil spray. Set aside.

Mix together brown sugar, oats, flour and flax seed meal with a fork. Add in butter and using a fork or your hands combine until a crumble forms. Will be sticky. Set aside.

Using a cookie scoop or large spoon, portion batter evenly into prepared muffin tins. There is a lot of batter and peaches so fill generously and fill to the top of the muffin tin.

Top with streusel-- gently press streusel into top of muffins.

Bake 22-25 minutes (22 minutes is perfect in my oven), or until the muffins are golden and toothpick inserted in the center comes out clean. If the tops are golden but the center not cooked, gently cover with foil and continue baking for the additional time.

Let muffins cool in muffin tin on wire rack for 10 minutes. Remove from tins and let cool at least another 10 minutes

Store in an air tight container for several days. Store in the refrigerator up to a week.