How to Make It
Preheat oven to 425°. Place 12 muffin-cup liners in muffin cups; coat liners lightly with cooking spray.
Weigh or lightly spoon all-purpose flour into dry measuring cups; level with a knife. Combine flour and next 4 ingredients (through baking soda) in a bowl, stirring with a whisk.
Place almond paste and sugar in a bowl; beat with a mixer at medium-low speed until mixture resembles sand (about 3 minutes). Add butter and vanilla; beat 2 minutes or until well combined. Add eggs, 1 at a time, beating well after each addition. Add flour mixture and milk alternately to butter mixture, beginning and ending with flour mixture; mix well after each addition.
Spoon half of batter into muffin cups. Top each with 1 teaspoon jam; divide remaining batter over jam. Sprinkle nuts over batter. Bake at 425° for 5 minutes. Reduce oven temperature to 375°. Bake at 375° an additional 10 minutes or until muffins spring back when touched lightly in center. Remove muffins from pan; place on a wire rack.
BAKE A SECOND BATCH
Double the muffin batter only if you have two (12-cup) pans. Alternate pans on the middle and top oven racks, and rotate halfway through baking. (You'll need to bake them an extra minute or two.) Ship these muffins without worry by dividing a batch between two large zip-top bags and cushioning them with tissue paper in a box.