Prep the pan and oven. Heat the oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease lightly.

Mix dry ingredients. In a medium bowl, whisk flour, baking powder, baking soda, and salt until combined.

Whisk wet ingredients. In a large bowl, whisk peanut butter, both sugars, eggs, milk, yogurt, oil, and vanilla until smooth. It will look creamy and slightly thick.

Combine gently. Add the dry ingredients to the wet bowl. Stir with a spatula just until no dry streaks remain. The batter should be thick but scoopable. Do not overmix.

Fill the cups, part one. Spoon about 1 tablespoon of batter into each muffin liner, just enough to cover the bottom.

Add the jam. Place 1 to 1 1/2 teaspoons of jam in the center of each cup. Keep it toward the middle so it doesn’t leak out.

Top with more batter. Divide the remaining batter over the jam, covering it completely. Each cup should be about 3/4 full.

Optional crunch. Sprinkle chopped peanuts or coarse sugar on top for texture.

Bake. Bake 16–20 minutes, until the tops are set and lightly golden. A toothpick inserted at the edge (not the jam center) should come out clean.

Cool. Let the muffins rest in the pan for 5 minutes, then move to a rack. Cool at least 10 more minutes before eating to avoid hot jam burns.