Combine the flour, sugar, baking powder and the salt in a mixing bowl. Cut in the peanut butter with two forks or a pastry blender until the mixture resembles coarse crumbs. Add the milk and eggs all at once, stirring until the flour is moistened. Place 2 Tb of the batter into a greased, fluted or plain muffin cup. Place 1 ts of the preserves in the center of the batter and top with 2 tb more of the batter. Repeat until you have dozen muffins. Bake in a 190ºC . oven for 15 to 17 minutes. Remove from the muffin cups and cool on a rack.